Estudio ultraestructural de la <i>Pars distalis</i> adenohipofisaria del coipo (Myocastor coypus)

Abstract

Por nuestro conocimiento no existen poblaciones concernientes a la ultraestructura de la adenohipófisis del Coipo. Este estudio tiene por objeto describir la estructura fina de las diferentes poblaciones celulares en la Pars distalis de la hipófisis del coipo adulto normal mediante técnicas convencionales para microscopía electrónica de transmisión: fijación en glutaraldehído post fijación en osmio e inclusión en resinas epoxy. Se emplearan 4 coipos machos y 4 hembras adultos mantenidos bajo condiciones naturales de luz, agua y alimento ad libitum. Se pudieron distinguir 5 tipos de células granuladas y 2 tipos de células no granuladas teniendo en cuenta principalmente la presencia de los gránulos de secreción y sus características. Las presentes observaciones efectuadas por primera vez en la adenohipófisis del coipo abren el camino para ampliar la información con nuevos estudios, especialmente basados en la inmunohistoquímica.

The fine structure of the Myocastor coypus (coypu) adenohypophysis was studied by conventional techniques by transmission electron microscopy The material was fixed in glutaraldehyde post-fixed in osmium tetroxide and embedded in epoxy resins Five types of granulated cells as well as two types of agranular cells could be identified taking into account mainly the present and characteristics of their secretory granules When these cells were compared to those previously described in other mammals such as humans rats and mice somatotrophic and gonadotrophic cells were fairly recognized However the possibility of detecting other cell types without the use of immunocytochemical methods was less reliable to the species studied the presence of highly developed population of follicular agranular cell must be emphasized The present observations, made for the first time in the coypo adenohypophysis would open the way by further studies on the field especially those based in immunohistochemistry.