Concentration of Oestrogens and Androgens in Human Ovarian Venous Plasma and Follicular Fluid Throughout the Menstrual Cycle

Abstract

The concentrations of androstenedione, testosterone, oestrone and oestradiol-17beta were measured in peripheral and ovarian venous blood and follicular fluid of women at various stages of the menstrual cycle. The concentration of oestradiol was similar in small follicles (diameter less than 8 mm) at all stages of the menstrual cycle and in large follicles (diameter greater than or equal to 8 mm) except during the mid- and late follicular phase when the concentration reached a peak (approximately 1500 ng/ml). The concentration of androstenedione was lowest in large preovulatory follicles at midcycle at a time when the secretion into the ovarian vein was markedly increased. The concentration of testosterone in large follicles (greater than or equal to 8 mm) was unchanged during the follicular phase whereas in small follicles there was a peak at mid-cycle. The rise in the concentration of testosterone and androstenedione at mid-cycle in peripheral plasma may be due to increased secretion by the preovulatory follicle into the ovarian vein. It is suggested that the relatively low concentration of androstenedione in follicular fluid of the preovulatory follicle arises from increased aromatization by granulosa cells in the course of oestrogen synthesis.

Effect of Reproductive Hormones on Ovarian Epithelial Tumors: I. Effect

“…The concentrations of E2 and P4 used in these studies were close to levels measured in the ovarian vein of premenopausal women. 7,8 We next examined the effect of gonadotropin hormones on thymidine incorporation in ML5 cells (Fig. 1B).…”

Manipulation of Human Ovarian Function: Physiological Concepts and Clinical Consequences*

“…AD and its immediate metabolite T are transferred from the theca layer to the intrafollicular compartment. For this reason these steroids are present in large quantities in ovarian follicles of all sizes and represent the main steroid produced by early antral follicles (73)(74)(75). Atretic follicles of all sizes (between 2 and 13 mm diameter) also contain high androgen levels (57, 76) and low E 2 concentrations (77).…”

Biological effects of stable overexpression of aromatase in human hormone-dependent breast cancer cells

“…Oestrogens are synthesised from androgens by an enzyme complex made up of the cytochrome P450 aromatase and the flavoprotein NADPH cytochrome P450 reductase (Lephart & Simpson, 1991). Aromatase activity is expressed in the endoplasmic reticulum of placenta (Fournet-Dulgerov et al, 1987) and also in ovarian granulosa cells (McNatty et al, 1976) and adipose tissue (Simpson et al, 1989), the main sites of oestrogen synthesis in pre-and post-menopausal women respectively.…”