THE PITUITARY GONADOTROPIC ACTIVITY OF STALK-SECTIONED MALE RATS1

Abstract

The effect of stalk section on the morphology and activity of the pituitary gland was investigated. Stalk section was found to cause anemic infarction of the anterior lobe, due to interruption of the circulation reaching it from the stalk, with subsequent shrinking of the gland, fibrosis and replacement of chromophils by chromophobes. The function of the damaged anterior lobe was impaired, as evidenced by atrophy of the testes, seminal vesicles, adrenals and thyroid glands and by decreased growth. Nevertheless, some of the stalk-sectioned rats displayed some degree of pituitary activity. Expts. utilizing stalk-sectioned, castrated rats indicated that the changes in pituitary basophils and pituitary gonadotropic potency caused by castration were severely affected by stalk section but not completely prevented. These results demonstrated that the relationships between the pituitary gland and the gonads of male rats were altered only quantitatively, in spite of complete interruption of the nervous and vascular connections between the hypothalamus and the anterior lobe.