Integrity of the portal vein is a condition for normal function of the reproductive tract in female rats. Section of the portal vein (PVS) always abolished periodic sexual function. In a series of 23 animals, 6 developed continuous estrus and other signs of the presence of excessive amounts of estrogenic hormones; yet the ovaries of these rats were small. In 6 other rats there was growth of the prostate and additional evidence of increased activity of androgenic hormones. Many rats failed to become pregnant and nearly all pregnant rats aborted. Except for a decrease in lipid content, the composition of the liver of PVS rats resembled that of intact mates in the criteria which were applied.
The rapid passage of blood through the liver is necessary to conjugate the excessive amounts of steroids which the rat ovary normally produces and an intact portal vein is an essential unit in the mechanism necessary for their partial inactivation.