Abstract
A staining technique is described to differentiate between the various types of cell in the anterior pituitary (growth hormone and prolactin producing cells, gonadotrophic, thyrotrophic and ACTH cells) in dogs, rats and rabbits. The method proved to be well reproducible and suitable for the routinely processed pituitary gland. The differentiating characteristics of this method for the prolactin and growth hormone producing cells were confirmed by the immuno-enzyme cytochemical technique in which specific anticanine prolactin and growth hormone sera were used. With this staining technique, the quantitative and qualitative characteristics of the different types of hypophyseal cells at various funtional and hormonal stages, under physiological and pathological conditions, can be studied. Effects of progesterone or oestrogen treatment on the morphology of the pituitary gland are illustrated in the photomicrographs.