Resumen de Aspectos ultraestruturales de trombocitos, eosinofilos y heterofilos de caiman crocodilus yacare (daudin, 1802) (reptilia, crocodilia)

Weber Leal de Moura, Luiz Waldemar Oliveira, Mizue Imoto Egami

• español

  Fueron utilizados 10 ejemplares de Caiman crocodilus yacare provenientes del municipio de Cáceres (Estado de Mato Grosso do Sul, Brasil), a cada uno de los cuales les fueron extraidos 5ml de sangre periférica. Las muestras obtenidas fueron utilizadas para análisis ultraestructurales, referentes a trombocitos, eosinófilos y heterófilos. Los trombocitos son de forma elíptica, poseen citoplasma abundante sólo en los polos y su núcleo presenta surcos profundos o hendiduras acentuadas, mostrando algunos poros en su envoltura. Su citoplasma contiene abundantes túbulos y vesículas electrolúcidas del sistema canalicular. Son observados vacúolas con cuerpos densos y microtúbulos. Los heterófilos poseen formato aproximadamente esférico y núcleo excéntrico o periférico. Su citoplasma está repleto de gránulos polimórficos de formas de huso, en baqueta, oval o esférica, con superficie, en general, irregular. Los eosinófilos son esféricos y de núcleo lenticular excéntrico o periférico. El citoplasma contiene gránulos esféricos u ovales. Cabe destacar la presencia de gránulos citoplasmáticos voluminosos con diferencias en la electrodensidad, de superficie uniforme, pudiendo contener una estructura interna heterogénea. En heterófilos y eosinófilos, el núcleo presenta heterocromatina, eucromatina, nucléolo y la envoltura nuclear es porosa

• English

  Little information is available on the ultrastructural characteristics of the blood cells in reptiles. In the present study we have examined the fine structure of heterophils, eosinophils and thrombocytes from the blood of a crocodile (Caiman crocodilus yacare). Samples of peripheral blood from healthy young were collected with EDTA and centrifuged. The buff coat was collected and fixed in half strength Karnovsky solution. Spindl-eshaped thrombocytes showed large nuclei with prominent heterochromatin juxtaposed to the nuclear envelop. Cytoplasmic organelles were scarce: there were mitochondria, some profiles of roughsurface endoplasmic reticulum, free ribosomes and microtubules. Many tubular structures and vacuoles were distributed throughout the cytoplasm, forming the open canalicular membrane system. Heterophils and eosinphils revealed round eccentric nuclei with prominent nucleoli. The cytoplasm of heterophils contained many polymorphic granules with homogeneous electrondense matrix. Ribosomes, roug-surfaced endoplasmic reticulum and many clear vesicles were observed. Some fibrillar structures were also present. In addition to the usual organelles, the cytoplasm of eosinophils were essentially filled with many round or slightly oval granules with heterogeneous electron-dense matrix; in some of them a fine granular structure was visible. Both heterophils and eosinophils showed long numerous pseudopodia