Sex Differences in Metabolic Effects of Oxytocin

Abstract

PRELIMINARY investigations in this laboratory showed that when synthetic oxytocin was administered intravenously to puerperal women at dosages between 10 mµ and 400 mµ/kg body-weight there occurred consistent increases in plasma non-esterified fatty acids (NEFA) in association with delayed hypoglycæmia¹. (The synthetic oxytocin (‘Syntocinon’) was kindly supplied by Dr. R. Bircher, medical director, Sandoz Pharmaceuticals, Hanover, New Jersey.) It was also shown that similar responses of NEFA and blood sugar follow oxytocin treatment in normal non-pregnant women without relation to pregnancy². In the latter subjects the hypoglycæmia was attended by consistent and significant falls in plasma inorganic phosphorus in contrast to small irregular increases occurring in puerperal women. These differences in phosphorus responses suggested the possibility of different mechanisms for the hypoglycæmia, but in both categories of subjects the blood sugar decreases were characteristic.