José Carretero
University of Salamanca, Anatomia E Histologia Humanas, Faculty Member
In order to determine whether corticosterone regulates activity of rat lactotrophs by acting directly at the pituitary level, immunohistochemical studies were carried out in adrenalectomized rats, subjected or not to treatment with... more
In order to determine whether corticosterone regulates activity of rat lactotrophs by acting directly at the pituitary level, immunohistochemical studies were carried out in adrenalectomized rats, subjected or not to treatment with corticosterone or colchicine, and in monolayer cultures after incubation with corticosterone. Adrenalectomy increased cellular and nuclear areas (p < 0.01) of prolactin-immunoreactive cells without affecting their cytoplasmic area. Similar results were found in adrenalectomized and colchicine-treated animals. Corticosterone reversed the effects of adrenalectomy, although normal values were partially reversed. In cultured pituitary cells, exposure to corticosterone reduced numerical density and cellular, cytoplasmic and nuclear areas with respect to control dishes. Morphological differences in shape, arrangement and nuclear features were observed after treatment with corticosterone. These results demonstrate an inhibitory effect of corticosterone on the...
Research Interests:
Prolactin (PRL) is a pituitary hormone that has been typically related to lactogenesis in mammals. However, it has been described over 300 roles in the organism of vertebrae and its relationship with the central nervous system (CNS) is... more
Prolactin (PRL) is a pituitary hormone that has been typically related to lactogenesis in mammals. However, it has been described over 300 roles in the organism of vertebrae and its relationship with the central nervous system (CNS) is yet to be clarified. Mainly secreted by the pituitary gland, the source of prolactin in the CNS remains unclear, where some experiments suggest active transport via an unknown carrier or, on the contrary, PRL being synthesized on the brain. So far, it seems to be involved with neurogenesis, neuroprotection, maternal behavior and cognitive processes in the hippocampus and dentate gyrus, among other regions.
Research Interests:
Research Interests:
Using rats subjected to immobilization stress, the aim of the present study was to investigate the expression of neuronal nitric oxide synthase and of its mRNA in the magnocellular neurons of the supraoptic nucleus of the hypothalamus,... more
Using rats subjected to immobilization stress, the aim of the present study was to investigate the expression of neuronal nitric oxide synthase and of its mRNA in the magnocellular neurons of the supraoptic nucleus of the hypothalamus, which does not have parvocellular neurons or direct neurohaemal connections with the anterior lobe of the hypophysis. nNOS expression was studied with immunohistochemistry using sheep anti-nNOS serum, and the intraneural detection of nNOS mRNA was accomplished using a non-isotopic in situ hybridization technique, employing a specific biotinylated probe. The acute stress elicited by restraint induced an increase in the overall size of the supraoptic nucleus, together with an increase in the number of magnocellular neurons expressing nNOS immunoreaction. The optical densitometry values of the nNOS immunoreaction, the nuclear areas of the immunoreactive neurons, and the density of neurons showing nNOS mRNA hybrids were higher in the supraoptic nucleus of...
Research Interests:
In order to characterize the pituitary cells re a ctive for r-GRF in the adult rat, an immunocytochemicaI and morphometric study was made of the cells immunopositive for r-GHRH and those immunopositive for GH and for GHRH using a double... more
In order to characterize the pituitary cells re a ctive for r-GRF in the adult rat, an immunocytochemicaI and morphometric study was made of the cells immunopositive for r-GHRH and those immunopositive for GH and for GHRH using a double labelling method. The existence of two populations of r- G R F - i m m u n o reactive cells was observed; one of these was only stained with specific serum against r-GRF and the other was immunopositively stained for GH and for r- G H R H . Morphometrically, in both sexes the GHi m m u n o reactive cells were seen to have a cellular size that was significantly larger (p<0.01) than the r- G H R H - i m m u n o reactive cells. The cells that were only stained for r-GHRH were significantly smaller than those immunoreactive for GH and r- G H R H . Our findings suggest the existence of at least two cellular populations in the pituitary gland of the adult rat able to react with anti-r-GHRH serum.
Research Interests:
The adrenomedullary chromaffin cells&#39; hormonal pathway has been related to the pathophysiology of diabetes mellitus. In mice, the deletion of insulin receptor substrate type 2 (Irs2) causes peripheral insulin resistance and... more
The adrenomedullary chromaffin cells&#39; hormonal pathway has been related to the pathophysiology of diabetes mellitus. In mice, the deletion of insulin receptor substrate type 2 (Irs2) causes peripheral insulin resistance and reduction in β-cell mass, leading to overt diabetes, with gender differences on adrenergic signaling. To further unravel the relevance of Irs2 on glycemic control, we analyzed in adult Irs2 deficient (Irs2) mice, of both sexes but still normoglycemic, dopamine effects on insulin secretion and glycerol release, as well as their adrenal medulla by an immunohistochemical and morphologic approach. In isolated islets, 10 μM dopamine significantly inhibited insulin release in wild-type (WT) and female Irs2 mice; however, male Irs2 islets were insensitive to that catecholamine. Similarly, on isolated adipocytes, gender differences were observed between WT and Irs2 mice in basal and evoked glycerol release with crescent concentrations of dopamine. By immunohistochemistry, reactivity to tyrosine hydroxylase (TH) in female mice was significantly higher in the adrenal medulla of Irs2 compared to WT; although no differences for TH-immunopositivity were observed between the male groups of mice. However, compared to their corresponding WT animals, adrenomedullary chromaffin cells of Irs2 mice showed a significant decrease in the cellular and nuclear areas, and even in their percentage of apoptosis. Therefore, our observations suggest that, together with gender differences on dopamine responses in Irs2 mice, disturbances in adrenomedullary chromaffin cells could be related to deficiency of Irs2. Accordingly, Irs2 could be necessary for adequate glucose homeostasis and maintenance of the population of the adrenomedullary chromaffin cells.
Research Interests:
The pituitary gland is part of hypothalamic-pituitary-gonadal axis, which controls development, reproduction, and aging in humans and animals. In addition, the pituitary gland is regulated mainly by hormones and neurotransmitters released... more
The pituitary gland is part of hypothalamic-pituitary-gonadal axis, which controls development, reproduction, and aging in humans and animals. In addition, the pituitary gland is regulated mainly by hormones and neurotransmitters released from the hypothalamus and by systemic hormones secreted by target glands. Aromatase P450, the enzyme responsible for the catabolization of aromatizable androgens to estrogens, is expressed in different parts of body, including the pituitary gland. Moreover, aromatase P450 is involved in sexual dimorphism where alteration in the level of aromatase can initiate a number of diseases in both genders. On the other hand, the direct actions of estrogens, mainly estradiol, are well known for stimulating prolactin release. Numerous studies have shown that changes in the levels of estrogens, among other factors, have been implicated in the genesis and development of prolactinoma. The pituitary gland can produce estradiol locally in several types of endocrine...
Research Interests:
In previous studies we demonstrated the expression of aromatase in pituitary cells. This expression is gender related, and is also associated with the presence of prolactinomas. To ascertain the relevance of aromatase in modulating the... more
In previous studies we demonstrated the expression of aromatase in pituitary cells. This expression is gender related, and is also associated with the presence of prolactinomas. To ascertain the relevance of aromatase in modulating the populations of prolactin-positive pituitary cells an immunocytochemical and morphometric study of prolactin-positive pituitary cells was carried out using the pituitary glands of adult male and female aromatase-knockout (ArKO) mice. Additionally has been determined if pituitary aromatase is involved in a gender-linked differentiated regulation of the prolactin-producing pituitary cells. Compared to wild-type mice, the knockout animals of both genders showed a significant decrease (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01) in the cellular and nuclear areas of their prolactin cells, as well as in the percentages of the prolactin-positive cells and the proliferating prolactin cells. Our results suggest that estradiol is responsible for the maintenance of the population of prolactin cell in males and, so as not to disturb the endocrine reproductive environment, estradiol is synthesized inside the pituitary by circulating testosterone via means of aromatase P450, which acts in paracrine way. This new role for pituitary aromatase may well explain the previous findings establishing that the pituitary expression of aromatase is higher in males than in females, and the association between the development of prolactinomas and the increased expression of aromatase in tumours.
Research Interests:
Research Interests:
Interleukins are proteins involved in the immune system and have been related to the endocrine regulation of the hypothalamic-pituitary-adrenal axis as well as to the secretion of ACTH, prolactin (PRL), GH and, possibly, LH. Like... more
Interleukins are proteins involved in the immune system and have been related to the endocrine regulation of the hypothalamic-pituitary-adrenal axis as well as to the secretion of ACTH, prolactin (PRL), GH and, possibly, LH. Like interleukin-6 (IL-6), vasoactive intestinal peptide (VIP) is synthesized in the pituitary gland and stimulates prolactin secretion. The aim of the present study was to address whether Interleukin 6 is involved in the regulation of VIP, as well as other factors involved in the regulation of prolactin such as dopamine, TRH and estradiol. Accordingly, we performed an in vitro study on monolayer cultures of rat pituitary cells, neutralizing the possible paracrine effect of IL-6 by immunosuppressing the protein by treatment with polyclonal antibody against IL-6 over 1, 3, 6 or 24 hours and then determining the degree of proliferation of VIP cells using double immunocytochemical labelling for VIP or PRL and proliferating cell nuclear antigen (PCNA). As a control,...
Research Interests:
Research Interests:
Research Interests:
Nowadays, obesity is considered as one of the main concerns for public health worldwide, since it encompasses up to 39% of overweight and 13% obese (WHO) adults. It develops because of the imbalance in the energy intake/expenditure ratio,... more
Nowadays, obesity is considered as one of the main concerns for public health worldwide, since it encompasses up to 39% of overweight and 13% obese (WHO) adults. It develops because of the imbalance in the energy intake/expenditure ratio, which leads to excess nutrients and results in dysfunction of adipose tissue. The hypertrophy of adipocytes and the nutrients excess trigger the induction of inflammatory signaling through various pathways, among others, an increase in the expression of pro-inflammatory adipocytokines, and stress of the endoplasmic reticulum (ER). A better understanding of obesity and preventing its complications are beneficial for obese patients on two facets: treating obesity, and treating and preventing the pathologies associated with it. Hitherto, therapeutic itineraries in most cases are based on lifestyle modifications, bariatric surgery, and pharmacotherapy despite none of them have achieved optimal results. Therefore, diet can play an important role in the ...
Research Interests:
Nowadays, obesity is considered as one of the main concerns for public health worldwide, since it encompasses up to 39% of overweight and 13% obese (WHO) adults. It develops because of the imbalance in the energy intake/expenditure ratio,... more
Nowadays, obesity is considered as one of the main concerns for public health worldwide, since it encompasses up to 39% of overweight and 13% obese (WHO) adults. It develops because of the imbalance in the energy intake/expenditure ratio, which leads to excess nutrients and results in dysfunction of adipose tissue. The hypertrophy of adipocytes and the nutrients excess trigger the induction of inflammatory signaling through various pathways, among others, an increase in the expression of pro-inflammatory adipocytokines, and stress of the endoplasmic reticulum (ER). A better understanding of obesity and preventing its complications are beneficial for obese patients on two facets: treating obesity, and treating and preventing the pathologies associated with it. Hitherto, therapeutic itineraries in most cases are based on lifestyle modifications, bariatric surgery, and pharmacotherapy despite none of them have achieved optimal results. Therefore, diet can play an important role in the ...
Research Interests:
The metabolism of triglycerides (TGs) is regulated, among others, by the lipoprotein lipase (LPL) that hydrolyses the TGs on endothelial cells. In turn, LPL is inhibited by the ANGPTLs family of proteins, such as ANGPTL3, 4, and, 8; the... more
The metabolism of triglycerides (TGs) is regulated, among others, by the lipoprotein lipase (LPL) that hydrolyses the TGs on endothelial cells. In turn, LPL is inhibited by the ANGPTLs family of proteins, such as ANGPTL3, 4, and, 8; the latter is the least known. In this work, we have tried to establish the expression and localisation of the Angiopoietin-like 8 (ANGPTL8) protein in the visceral adipose tissue (VAT) of morbid-obese and non-obese patients. 109 subjects (66 women and 43 men) undergoing laparoscopic surgery participated in this study. A blood sample and a portion of the VAT were obtained, and the patients were classified according to their Body Mass Index (BMI) as non-obese (19.5–30 kg/m2) and morbid-obese (40–50 kg/m2). No significant changes in ANGPTL8 plasma levels were determined by EIA in obese patients. The immunocytochemistry and Western blotting showed the presence of increased ANGPTL8 in morbid-obese patients (p < 0.05). In-situ hybridisation and a real time...
Research Interests:
The metabolism of triglycerides (TGs) is regulated, among others, by the lipoprotein lipase (LPL) that hydrolyses the TGs on endothelial cells. In turn, LPL is inhibited by the ANGPTLs family of proteins, such as ANGPTL3, 4, and, 8; the... more
The metabolism of triglycerides (TGs) is regulated, among others, by the lipoprotein lipase (LPL) that hydrolyses the TGs on endothelial cells. In turn, LPL is inhibited by the ANGPTLs family of proteins, such as ANGPTL3, 4, and, 8; the latter is the least known. In this work, we have tried to establish the expression and localisation of the Angiopoietin-like 8 (ANGPTL8) protein in the visceral adipose tissue (VAT) of morbid-obese and non-obese patients. 109 subjects (66 women and 43 men) undergoing laparoscopic surgery participated in this study. A blood sample and a portion of the VAT were obtained, and the patients were classified according to their Body Mass Index (BMI) as non-obese (19.5-30 kg/m 2) and morbid-obese (40-50 kg/m 2). No significant changes in ANGPTL8 plasma levels were determined by EIA in obese patients. The immunocytochemistry and Western blotting showed the presence of increased ANGPTL8 in morbid-obese patients (p < 0.05). In-situ hybridisation and a real ti...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Among the more than 300 biological actions described for prolactin, its role in the neurogenic capacity of the hippocampus, which increases synaptogenesis and neuronal plasticity, consolidates memory and acts as a neuronal protector... more
Among the more than 300 biological actions described for prolactin, its role in the neurogenic capacity of the hippocampus, which increases synaptogenesis and neuronal plasticity, consolidates memory and acts as a neuronal protector against excitotoxicity-effects mediated through its receptors are more recently known. The detection of prolactin in the hippocampus and its receptors, specifically in the Ammon's horn and dentate gyrus, opened up a new field of study on the possible neuroprotective effect of hormones in a structure involved in learning and memory, as well as in emotional and behavioral processes. It is currently known, although controversial, that prolactin may be related to sex and age and that the hormone could be synthesized in the hippocampus itself. However, the regulatory mechanisms of changes in prolactin or in its hippocampal receptors still remain unknown. This review introduces the reader to general aspects concerning prolactin and its receptors and to wha...
Research Interests:
Among the more than 300 biological actions described for prolactin, its role in the neurogenic capacity of the hippocampus, which increases synaptogenesis and neuronal plasticity, consolidates memory and acts as a neuronal protector... more
Among the more than 300 biological actions described for prolactin, its role in the neurogenic capacity of the hippocampus, which increases synaptogenesis and neuronal plasticity, consolidates memory and acts as a neuronal protector against excitotoxicity-effects mediated through its receptors are more recently known. The detection of prolactin in the hippocampus and its receptors, specifically in the Ammon's horn and dentate gyrus, opened up a new field of study on the possible neuroprotective effect of hormones in a structure involved in learning and memory, as well as in emotional and behavioral processes. It is currently known, although controversial, that prolactin may be related to sex and age and that the hormone could be synthesized in the hippocampus itself. However, the regulatory mechanisms of changes in prolactin or in its hippocampal receptors still remain unknown. This review introduces the reader to general aspects concerning prolactin and its receptors and to wha...
Research Interests:
Interleukin-1 beta (IL-1β) is a cytokine linking the neuroendocrine system and metabolic homeostasis. We have previously demonstrated the relevance of IL-1β for maintaining the pituitary ACTH-producing cells by immuno-blocking its effects... more
Interleukin-1 beta (IL-1β) is a cytokine linking the neuroendocrine system and metabolic homeostasis. We have previously demonstrated the relevance of IL-1β for maintaining the pituitary ACTH-producing cells by immuno-blocking its effects in pituitary cultures. However, the morphological characteristics and the intimate relationship of the pituitary cells expressing IL-1β and ACTH remain unknown. For determining pituitary variations of immunoreactivity for IL-1β and its relation with ACTH-positive cells under stress situations, we performed an immunohistochemical analysis of the expression of IL-1β and ACTH in the pituitary gland of adult rats, in the absence or presence of corticosterone, by establishing different groups: untreated, sham-operated, and bilaterally adrenalectomized animals. In the rats subjected to surgery, the glucocorticoid was administered on the same day of the intervention and on the third day post-surgery. Interestingly, it was observed that IL-1β was located i...
Research Interests:
A scanning electron microscope study was made of the surface of the organum vasculosum laminae terminalis of the rat, dog and cat. The ependyma of this organ, in all three species, is lacking in cilia or is only monociliate; it exhibits... more
A scanning electron microscope study was made of the surface of the organum vasculosum laminae terminalis of the rat, dog and cat. The ependyma of this organ, in all three species, is lacking in cilia or is only monociliate; it exhibits numerous supraependymal processes and cell bodies and in the different species studied there are differences that affect the number, size and distribution of the supraependymal cells. There is a great richness of vessels in the supraepedymal layer of the organum vasculosum laminae terminalis.
Research Interests:
Research Interests:
Research Interests:
By means of the peroxidase-antiperoxidase technique a comparative immunocytochemical study of the distribution of the vasotocin- and vasopressin-reacting system in the chicken and rat hypothalamus was carried out. In both species it is... more
By means of the peroxidase-antiperoxidase technique a comparative immunocytochemical study of the distribution of the vasotocin- and vasopressin-reacting system in the chicken and rat hypothalamus was carried out. In both species it is possible to distinguish, on the basis of their topographical location, three different comparable populations: The first one is situated very close to the pial surface and the optic chiasma (L1 and L2 groups in the chicken and the supraoptic nucleus in the rat). The second one is located near to the third ventricle and corresponds to the suprachiasmatic nucleus of both species and the periventricular groups of the chicken (P1, P2, and P3 groups) and the periventricular subdivision of the paraventricular nucleus of the rat. The third one is situated between the two previous populations and consists of small clusters of reacting neurons (L3 and L5 groups in the chicken and the nucleus circularis and fornicalis in the rat) and to a large cluster of react...
Research Interests:
Los paragangliomas son neoplasmas procedentes de paraganglios extraadrenales que derivan de la migración de las células de la cresta neural durante el desarrollo embrionario. Según su distribución anatómica, su inervación y su estructura... more
Los paragangliomas son neoplasmas procedentes de paraganglios extraadrenales que derivan de la migración de las células de la cresta neural durante el desarrollo embrionario. Según su distribución anatómica, su inervación y su estructura microscópica, pueden ser agrupados en familias interrelacionadas, diferenciándose paraganglios branquioméricos (relacionados con los arcos y hendiduras branquiales), intravagales, aórtico-simpáticos y autonómicos-viscerales. Los paragangliomas cervicocefálicos pertenecen principalmente a las 2 primeras de estas familias. El presente capítulo está divido en 2 partes. En la primera parte se hace una revisión sobre su origen embriológico, poniendo especial énfasis en el proceso de neurulación o formación del tubo neural; la neurosegmentación, resumiendo los mecanismos implicados en la segmentación inicial del tubo neural y la segmentación del rombencéfalo y la médula espinal, y la evolución de las placodas sensitivas e inducciones secundarias en la reg...
Using the peroxidase-antiperoxidase immunocytochemical technique, a morphometric study of the magnocellular neurons of the Paraventricular nucleus of the rat hypothalamus, reactive to specific anti-vasopressin rabbit serum, was made.... more
Using the peroxidase-antiperoxidase immunocytochemical technique, a morphometric study of the magnocellular neurons of the Paraventricular nucleus of the rat hypothalamus, reactive to specific anti-vasopressin rabbit serum, was made. Following systemic and chronic administration of met-enkephalin the number of immunoreactive neurons was higher, especially in females. Additionally, in the females, it was possible to observe an increase in the immunoreactivity and the presence of well-stained fibres. These findings suggest, especially in females, a blockage in the release of vasopressin, facilitating its immunocytochemical visualization.
Research Interests:
An ultrastructural and morphometric study of Kurosumi et al. (1986) on type 1 GH cells in adult Sprague-Dawley rats, after the intraventricular administration of Met-enkephalin, with or without prior intraperitoneal administration of... more
An ultrastructural and morphometric study of Kurosumi et al. (1986) on type 1 GH cells in adult Sprague-Dawley rats, after the intraventricular administration of Met-enkephalin, with or without prior intraperitoneal administration of naloxone, was carried out and then compared to the same cellular type of untreated animals and of animals intraventricularly treated with distilled water, used as controls. The study demonstrated an increase of cellular (p < 0.05) and nuclear (p < 0.05) areas, an enlargement and dilation of the cisternae of the Golgi complex, with an increase in the Golgi area (p < 0.01) and the immature granules (p < 0.01); a greater development of the rough endoplasmic reticulum and an increase in the number of exocytosis (p < 0.01) and, only in male rats, an increase in the mature secretory granules (p < 0.01). The prior administration of naloxone prevented the appearance of these changes and also produced an increase (p < 0.01) of the organelles...
Research Interests: Growth Hormone, Female, Animals, Male, Endoplasmic Reticulum, and 4 moreRats, Sex Factors, Golgi Apparatus, and Naloxone
Using a combined scanning and electron microscope technique, the repercussion on the rostral wall of the III ventricle in a patient affected with a retrochiasmatic craniopharyngioma with growth in the ventricular direction were analysed.... more
Using a combined scanning and electron microscope technique, the repercussion on the rostral wall of the III ventricle in a patient affected with a retrochiasmatic craniopharyngioma with growth in the ventricular direction were analysed. The apical surface of the ependymocytes was found to be free of cilia, although there were numerous microvilli. The most striking finding appreciated with the scanning electron microscope was the presence of bulbous protrusions towards the lumen of the ventricle; these were formed of cells with shapes, sizes and surface characteristics different from the rest of the ependyma, which appeared flattened. The ultrastructural study revealed the presence of large numbers of filaments and junction complexes both in the ependymal and subependymal cells. Additionally, the protruded zones corresponded to areas showing different degrees of cellular disorganization.
Research Interests:
Following administration of met-enkephalin into the third ventricle of rats of both sexes, an ultrastructural-morphometric study was carried out of the neural lobe of the hypophysis, comparing the results with those obtained in untreated... more
Following administration of met-enkephalin into the third ventricle of rats of both sexes, an ultrastructural-morphometric study was carried out of the neural lobe of the hypophysis, comparing the results with those obtained in untreated animals, controls (injected intraventricularly with distilled water) and animals previously receiving naloxone intraperitoneally. In the untreated and control animals, both males and females, there was a high percentage (about 70%) of neurosecretory axons considered to have a normal morphology; after met-enkephalin administration, this percentage decreased and was accompanied by a rise (slightly more pronounced in the females) in the percentage of degranulated axons and a slight rise in axons with a morphology indicative of regenerative and degenerative phases. Previous administration of the opiate antagonist naloxone led to a rise in the number of axons in the degenerative phase with respect to the other groups of animals; this occurred in both sexes.
Research Interests:
A morphometric-ultrastructural study was made of the supraoptic nucleus of rats of both sexes following central administration of met-enkephalin. Ten minutes after met-enkephalin treatment the number of axo-somatic synapses was... more
A morphometric-ultrastructural study was made of the supraoptic nucleus of rats of both sexes following central administration of met-enkephalin. Ten minutes after met-enkephalin treatment the number of axo-somatic synapses was significantly increased. This effect was more pronounced in female rats than in males and could be prevented by preceding administration of naloxone. Animals that received naloxone followed by met-enkephalin showed a dilation of the rough endoplasmic reticulum into a vesicular shape. Our results provide preliminary evidence for a fast remodeling of synaptic input to magnocellular hypothalamic neurons. It is likely that the known inhibitory action of opioids on the hypothalamo-neurohypophysial system is partly mediated by this plasticity.
Research Interests:
In order to elucidate whether the gender differences observed in the somatotropic cells of adult rats are mediated by hypothalamic neuropeptides, a morphometric analysis was made of the GH-immunoreactive cells of adult rats treated... more
In order to elucidate whether the gender differences observed in the somatotropic cells of adult rats are mediated by hypothalamic neuropeptides, a morphometric analysis was made of the GH-immunoreactive cells of adult rats treated intraventricularly with colchicine. The morphometric and morphological findings obtained were correlated to the basal serum levels of GH at the time of sacrifice. Treatment with colchicine was seen to increase serum GH levels; this increase was accompanied by an increase in the intensity of the reaction of the GH-cells and, morphometrically, an increase in their size due to an increase in the nuclear area, but with no significant changes in the cytoplasmic area. The results suggest that in the absence of somatostatin and GRF the basal release of GH is elevated in a similar fashion in both sexes, in turn suggesting that gonadal steroids might act at hypothalamic level on the release of somatostatin and, indirectly, on the intracellular pool of GH and hormo...
Research Interests:
The current study was performed to analyse the potential existence and structure of a GHRH-transporting tuberoinfundibular system in the rat median eminence. The immunocytochemical analysis using anti-GHRH revealed an intense... more
The current study was performed to analyse the potential existence and structure of a GHRH-transporting tuberoinfundibular system in the rat median eminence. The immunocytochemical analysis using anti-GHRH revealed an intense immunoreaction in the ependimary cells, tanycytes, at the level of the floor of the infundibular recess forming part of the median eminence. The basal processes of these cells course towards the external layer of the median eminence and reach the growth hormone-releasing hormone (GHRH) fibres of the tuberoinfundibular tract and this reaction was increased after intraventricular treatment with colchicine. Thus, these observations suggest the existence of a second or alternative cerebrospinal fluid-mediated route of GHRH transport to the median eminence and implicate the involvement of tanycytes in the regulation of this novel transport system.
Research Interests: Immunohistochemistry, Hypothalamus, Female, Animals, Male, and 5 moreRats, Folia, Ependyma, Median Eminence, and Third ventricle
Research Interests:
Research Interests:
Research Interests:
The morphological-morphometric consequences of bilateral adrenalectomy on vasopressin-reacting neurons of the paraventricular nucleus of the rat hypothalamus were analyzed. Bilateral adrenalectomy led to a dramatic increase in the... more
The morphological-morphometric consequences of bilateral adrenalectomy on vasopressin-reacting neurons of the paraventricular nucleus of the rat hypothalamus were analyzed. Bilateral adrenalectomy led to a dramatic increase in the cellular area as well as the number of immunoreactive cells (when compared to those obtained in normal colchicine-treated animals) in the neurons located in the anterior, medial and periventricular parvicellular subdivisions of the paraventricular nucleus. By contrast, no changes were observed in either the dorsal or lateral parvicellular subdivisions or in any of the magnocellular subdivisions of the paraventricular nucleus.
Research Interests:
Research Interests:
Research Interests:
The effect of verapamil, a calcium channel blocker, on endothelin-1 (ET-l)-induced mesangial cell proliferation was assayed. Rat mesangial cells (primary cultures) were maintained in... more
The effect of verapamil, a calcium channel blocker, on endothelin-1 (ET-l)-induced mesangial cell proliferation was assayed. Rat mesangial cells (primary cultures) were maintained in 0.5&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;percnt; fetal calf serum medium for 2 days and then incubated with ET-1 and verapamil for 24 h. ET-1 induced a dose-dependent [3H]thymidine uptake (peak at 10-7M; 773 ± 85&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;percnt; over basal, serum-deprived cells), protein synthesis
Research Interests:
In order to elucidate the existence of gender-related variations in both growth hormone (GH) release and the activity of somatotropic cells following bilateral adrenalectomy, a morphometric analysis was performed on GH-immunoreactive... more
In order to elucidate the existence of gender-related variations in both growth hormone (GH) release and the activity of somatotropic cells following bilateral adrenalectomy, a morphometric analysis was performed on GH-immunoreactive cells from adult male and female rats after bilateral adrenalectomy, correlating the findings with the serum levels of the hormone. The results obtained were compared to those found in untreated animals. Bilateral adrenalectomy was seen to induce a decrease in serum GH levels (p less than 0.01) in male rats; this was accompanied by a significant decrease in cellular area (p less than 0.01), cytoplasmic area (p less than 0.05) and nuclear area (p less than 0.01) and by a decrease in the cytoplasmic immunoreaction intensity of GH cells. By contrast, the above-mentioned changes did not appear in the female rats. These results suggest that the action of glucocorticoids on the synthesis and release of GH depends on the sex of the animal.
Research Interests:
Research Interests:
Research Interests:
Research Interests: Cognitive Science, Brain, Hypothalamus, Female, Animals, and 3 moreSupraoptic Nucleus, Rats, and Neurosciences
Tolerance and dependence are the most important side effects of opioid-mediated pain therapies. However, the mechanisms through which these phenomena are produced still remain unknown. Among the opioid receptors, the kappa-opioid receptor... more
Tolerance and dependence are the most important side effects of opioid-mediated pain therapies. However, the mechanisms through which these phenomena are produced still remain unknown. Among the opioid receptors, the kappa-opioid receptor has been the focus of strong research efforts, since it contributes to the reversal of morphine-induced tolerance and dependence. Parallel to this, neuronal nitric oxide synthase has been shown to play a key role in the development of these unwanted effects. Both the kappa-opioid receptor and neuronal nitric oxide synthase are abundantly located in the CNS. One of the areas where these cellular agents are best represented is a key encephalic nucleus in the development of tolerance to the analgesic action of opioid drugs, the periaqueductal gray. In this work, we studied whether morphine-induced tolerance and dependence causes changes (a) in the activity of neuronal nitric oxide synthase and (b) in kappa-opioid receptor expression in the rat periaqueductal gray. Besides, we examined the colocalization of both molecules. Our results point to an involvement of KOR and nNOS in the same intracellular network that controls the development of morphine tolerance and dependence.
Research Interests:
Research Interests:
In order to elucidate the response of somatotropic cells to the influence of gonadal steroids on the regulation of growth hormone secretory patterns, a morphometric analysis was carried out on the GH-immunoreactive cells of adult male... more
In order to elucidate the response of somatotropic cells to the influence of gonadal steroids on the regulation of growth hormone secretory patterns, a morphometric analysis was carried out on the GH-immunoreactive cells of adult male rats treated chronically with intramuscular injections of estradiol valerate. The morphometric and morphological results obtained were correlated to the serum levels of GH at the moment of sacrifice. Treatment with a daily dose of 125 micrograms of estradiol vaterate over 15 d was seen to lead to an increase (p less than 0.01) in the serum GH values accompanied by a decrease in the intensity of reaction of the GH-cells and, morphometrically, a reduction in their size (p less than 0.01) due to a decrease in the cytoplasmic area (p less than 0.01), but without significant changes in the nuclear area. Our results suggest that in male rats estrogens enhance the release of the intracellular GH pool but that they do not affect hormone synthesis to a great extent.