PERINATAL CONCENTRATIONS OF PROGESTERONE, LACTOSE AND α-LACTALBUMIN IN THE MAMMARY SECRETION OF WOMEN

Abstract

Departments of Biochemistry and *Obstetrics and Gynaecology, University of Western Australia, Nedlands, Australia (Received 25 April 1977) The hormonal signal for lactogenesis in a number of different species is considered to be a precipitous fall in the concentration of progesterone in the blood during late pregnancy (see Hartmann, Trevethan & Shelton, 1973). In women, the major fall in the level of blood progesterone just after delivery (Yannone, McCurdy & Goldfien, 1968) precedes lactogenesis by 2-3 days (Reynolds, 1972). However, the effects of this fall may be modified to some extent by progesterone, which accumulates in the milk (Heap, Gwyn, Laing & Walters, 1973). Progesterone could be the 'lipid-soluble substance' in the mammary secretion which Linzell & Peaker (1974) suggested might control the final stage of lactogenesis. The purpose of the present investigation was to compare changes in the concentrations of progesterone, lactose and α-lactalbumin in the mammary secretion of women