Ultrastructural changes in the adenohypophysis during the ovarian cycle of the viviparous teleost Poecilia latipinna. III. The growth hormone, adrenocorticotrophic, and prolactin cells and the pars intermedia.

During the monthly cycle of vitellogenesis, intraovarian gestation, and parturition, the pituitary growth hormone (GH) cells show ultrastructural changes indicative of an increase in secretory activity related to vitellogenesis. In contrast, the pituitary adrenocorticotrophic (ACTH) cells are relatively inactive during vitellogenesis, but become active… CONTINUE READING