Histology of the Pituitary, Testis, and Adrenal in Relation to Reproduction in the Bull

Abstract

The relation between the histology of the endocrine organs and reproduction in bulls has not been studied extensively. Most of the reports dealing with normal and impaired fertility have been limited to the changes occurring in a single organ. In order to estimate the relative importance of the several possible causes of impaired fertility, the histology of the pituitary, adrenal, and testis in bulls is being studied at this station. Smith and Smith (11) described the separation of the anterior lobe of the bovine pituitary into a central and peripheral zone. Bassett (1) described the central portion of the anterior lobe as a core running through the gland. She also stated that the peripheral portion of the lobe contains many alpha cells, whereas the central portion is devoid of alpha cells but rich in beta cells. Bassett (1) and Hall (6) described two kinds of beta cells in the anterior pituitary of cattle. Garm (4) described the following cell types in the anterior lobe of normal dairy cows: acidophils with small nucleus, acidophils with large nucleus, small basophils, large basophils, hyaline basophils, and heterotrophic amphophils. He believed that the last type of cell represents a late functional stage of hyaline basophils. He described the hyaline basophils as large basophils with pale pink homogenous areas in the cytoplasm. Cows with nymphomania showed no change in acidophils but an increase in frequency of large basophils, chromophobes with a large nucleus, hyaline basophils, and hypertrophic amphophils. Gilmore et al. (5) have studied the bovine hypophysis in relation to breed, age, milk production, and sex. They studied the gland by making statistical analyses of cell counts on comparable sections of the gland. They described an acidophil that seemed to be related to the sexual activity of the animal. Friedman and Hall (3) and Smelser (10), studying the pituitary of the steer, reported higher concentrations of gonadotrophin in the central core and of prolactin in the peripheral zone of the anterior lobe. These differences in the concentrations of hormones were not noted in the pituitaries of cows. Bassett (1) reported that the small basophil cells were virtually absent in steer glands but were increased and prominent in cows treated with stilbestrol and in pregnant