Prolactin and Hysterectomy Delay Rather Than Prevent the Critical Need for LH (LH Dependency) in the Luteotrophic Process of the Rat 1

Abstract

Abstract

The corpus luteum (CL) of the pseudopregnant rat normally becomes dependent on LH by Day 9 for the maintenance of progesterone production. The effects of hysterectomy or treatment with prolactin on the development of LH dependency by rat corpora lutea (CL) was studied by subjecting rats to one of the following procedures: hysterectomy before the induction of pseudopregnancy (“chronic hysterectomy”); hysterectomy on Day 2 of pseudopregnancy; hysterectomy on Day 5 of pseudopregnancy, combined with prolactin treatment by homotransplantation of a single donor pituitary on Days 2 or 5; hysterectomy on Day 2 of pseudopregnancy combined with homotransplantation of one or four pituitaries on Day 2. In each of these conditions, treatment with an antiserum to LH (LHAS) on Day 9 does not result in luteolysis (5). However, treatment with LHAS on Day 12 was able to cause luteolysis. Early hysterectomy and prolactin, therefore, act similarly to delay rather than prevent the dependency of the rat's corpora lutea on LH as a luteotrophin.