Blood flow: a mediator of ovarian function

Abstract

Data from several studies are presented which suggest that blood flow to the corpus luteum may be important in the regulation of this gland. Blood flow to the luteal ovary increases from less than 1 ml/min to 3 to 7 ml/min as the corpus luteum develops and is maintained. During regression, blood flow to the luteal ovary declines sharply. When ewes were administered PGF2α or analogs of PGF2α serum levels of progesterone and blood flow to the luteal ovary declined to basal levels within 6 h. The hemodynamic changes associated with luteal regression in PGF2α treated ewes were similar to those observed in cycling ewes. Finally, regional blood flow within the corpus luteum was studied using 15 μ radioactive microspheres. When small pieces of tissue were taken following infusions of HCG 125I and 85Sr microspheres into the ovarian artery the cpm/mg tissue of the two isotopes were highly correlated. These data suggest that the specific binding of HCG to luteal cells is influenced by the flow of blood to these cells. From these studies it appears that blood flow may be an important factor in regulating the activity of the gonadotropic hormones at the luteal cell level. It further appears that a secondary mechanism of action of LH may be to increase blood flow to the corpus luteum.