THE EFFECT OF PITUITARY STALK SECTION UPON REPRODUCTIVE PHENOMENA IN THE FEMALE RAT1

Abstract

Reproductive cycles, ovulation, mating, pregnancy and lactation are normal after section of the pituitary stalk in the rat. The depressing action of cold upon the reproductive cycle and the ovary is abolished by pituitary stalk section. Hypophyseal deficiency sometimes occurs after pituitary stalk section. It is apparently a result of inadvertent damage to the ant. pituitary or its blood supply, and does not represent a physiological effect of denervation. Activation of such deficient pituitariea sometimes occurs after injs. of pregnancy urine extracts. The pituitary stalk mechanism modifies the rate of production of thyrotrophic and gonadotrophic hormones in response to certain emergency situations.