An immunohistochemical study of adenohypophyseal cells in the viviparous reptile Chalcides chalcides

The morphology of the hypophysis and the immunocharacteristics of the adeno hypophyseal cells in the viviparous reptile Chalcides chalcides were studie d by light microscopy, using conventional staining methods and an indirect antibody technique (ABC method), respectively. The general morphology of th e C. chalcides hypophysis was comparable to that of other reptiles, showing three main regions: the pars distalis, the pars intermedia and the pars ne rvosa. The gland appeared as an elongated body in a cephalic-caudal directi on and was almost completely enclosed in the sella turcica. For this reason , the hypophysis was studied in toto with the brain in decalcified specimen s. The pars distalis accounted for most of the whole organ. The pars interm edia surrounded the pars nervosa as a goblet. The pars tuberalis was lackin g. The immunohistochemical identification of the adenohypophyseal cells was pe rformed using rabbit antisera against mammalian/ synthetic hypophyseal horm ones. Prolactin cells were clustered in small cellular cordons in the rostr al pars distalis and in the medial pars distalis in both male and female sp ecimens. Somatotropic cells were found in the caudal pars distalis. Cortico tropic cells were observed in the medio-rostral pars distalis, as well as i n the pars intermedia, where melanotropic cells were also present. Melanotr opic cells were confined to the pars intermedia. Gonadotropic cells were mo stly distributed in the ventral and lateral portions of the pars distalis, where they were found isolated or in small clusters. Thyrotropic cells were detected in the pars distalis with a distribution similar to that of the g onadotropic cells; however, atypically, they were also found in the pars in termedia. Therefore, the cytological characteristics of the adenohypophysea l cells appeared mostly conserved.