Gonadotropic Activity of Chicken Pituitary Glands

Abstract

Pituitary glands from intactmale chickens and capons castrated at 40 days of age were assayed for gonadotropic content. There was no difference in the gonadotropic activity of glands from the 2 groups prior to 90 days of age. The pituitaries from castrate males were significantly lower in gonadotropin than those from intact males of the same age during the period of 120 to 210 days of age. This difference between these 2 groups during this period was not apparent when the gonadotropic activity was calculated on a per gland basis. The hypertrophy of the glands following castration apparently resulted in a decrease in activity on a per unit weight basis, but there was not a significant change in the total activity per gland. A comparison of the gonadotropic activity of pituitary glands from the chicken, turkey and rat was made by assaying 10 mg of fresh pituitary tissue from each species in the immature female rat, 3-day-old turkey poult and 3-day-old chick. The ovaries of the immature rats responded only to gonadotropin from the rat. The chick testes were sensitive to pituitary gonadotropin from all 3 species and, although the turkey testes were sensitive to gonadotropin from the chicken and the rat, they did not respond to turkey pituitary gonadotropin.