Vascular dynamics of the reproductive tract in the female rhesus monkey: relative contributions of ovarian and uterine arteries

Abstract

The anatomical descriptions of the vasculature of the uterus and ovaries in rhesus monkeys do not provide quantitative information about the relative contributions of the ovarian and uterine arteries to the blood supply of the reproductive tract. To identify the major source of arterial blood supply to these organs under varying reproductive conditions, monkeys were studied during nonpregnant (n = 7), early pregnant (days 13-18, n = 6), and late pregnant (days 149-154, n = 4) states. Microspheres, labelled with different isotopes, were injected simultaneously into the left ventricle and the aorta midway between the origin of the ovarian artery and the terminal bifurcation of the aorta. The resulting ratio of microspheres in various organs or segments of the reproductive tract was indicative of the source of arterial blood. There was no significant difference in the source of arterial blood between nonpregnant and early pregnant monkeys; under both circumstances the uterine artery supplied 91 to 100% of the arterial blood reaching all segments of the reproductive tract. However, during late pregnancy, blood supply via the uterine artery to the ovaries and oviducts decreased (P < 0.01) to 9 and 5%, respectively; the average uterine arterial contribution to the cranial segment of the uterus was reduced to 63% and that to the middle and caudal uterus was unchanged. Considering all stages studied, there was no unilateral difference in distribution of arterial blood to the reproductive tract even in the presence of an active corpus luteum. Thus, the ovarian artery appears to be largely nonfunctional in supplying blood to the reproductive tract except during late pregnancy when the ovarian artery becomes dominant in providing blood to the ovaries and oviducts.