Influence of nitric oxide synthase inhibition on vasopressin and corticosterone secretion during water deprivation in rats

• Autores: Bessem Mornagui, Raja Rezg, Abir Grissa, Monique Duvareille, Claude Gharib, Abdelaziz Kamoun, Saloua El-Fazaa, Najoua Gharbi
• Localización: Journal of physiology and biochemistry, ISSN-e 1877-8755, ISSN 1138-7548, Vol. 66, Nº. 4, 2010, págs. 271-281
• Idioma: inglés
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• Resumen

  • Nitric oxide (NO) is a short-lived radical that functions as a neurotransmitter in the central nervous system and plays a physiological role in the regulation of hypothalamic�pituitary�adrenal axis and vasopressinergic axis. In the present study, we aimed to investigate the interaction between the generation of NO and vasopressin (AVP) and corticosterone release after 3 days of water deprivation in rats. Animals were previously treated with intraperitoneal (i.p.) saline or l-nitro-arginine methyl ester (L-NAME) injection. l-NAME is a nonspecific inhibitor of nitric oxide synthases. In control rats given i.p. saline or l-NAME, hypothalamic, pituitary, and plasma AVP levels and plasma corticosterone did not change from baseline levels (p > 0.05). Three days of water deprivation increased significantly the corticosterone levels in plasma (p < 0.01) and AVP levels in hypothalamus and plasma (p < 0.01), but not in pituitary, which showed a significant decrease. These variations were concomitant with the elevation of nitrates/nitrates in plasma. l-NAME injection abolished significantly (p < 0.01) the elevation of plasma corticosterone and hypothalamic AVP levels induced by water deprivation. These findings showed that in water-deprived rats, nitric oxide synthase inhibition by l-NAME inhibits corticosterone and vasopressin release, suggesting a potent stimulatory role of NO.