STUDIES ON THE MECHANISM OF NIDATION XIV. THE CATECHOLAMINE CONTENT OF THE UTERUS, OVARY AND HYPOPHYSIS DURING EARLY PREGNANCY

Abstract

SUMMARY Uterine, ovarian, and hypophysial catecholamines in rats were measured daily during the first 6 days of pregnancy. A marked decrease in uterine adrenaline was observed between L3 and L4 of pregnancy. (L0 was the day when postcoital spermatozoa were observed in the vaginal smear. L1, L2, etc., denote leucocyte type smears.) Daily fluctuations in ovarian catecholamines as well as a rise in hypophysial catecholamines between L2 and L3 followed by a reduction thereafter were observed. The results suggest a correlation between the 'oestrogen surge' on L3 of pregnancy and the reduction of uterine adrenaline and hypophysial adrenaline and noradrenaline. The rise in hypophysial catecholamines was related to the hypothalamic stimulation of hypophysial gonadotrophic activity on L2 of pregnancy.