The use of an indicator diffusion procedure to measure the uterine blood flow in sows during the estrous cycle and pregnancy.

Abstract

Uterine blood flow was measured in 16 nonpregnant sows and 13 pregnant sows at selected points during the estrous cycle and pregnancy. The 4-aminoantipyrine indicatordiffusion method was employed and measurements were made while the animals were under halothane anesthesia. In nonpregnant females, the uterine blood flow per kilogram of uterus was greater at 1 day and 19 days following estrus than at 5 or 14 days. The uterine weight was markedly increased at 14 days resulting in a slight elevation of total uterine blood flow at this stage as compared to the other three times during the cycle. Uterine tissue-uterine venous blood ratios indicated that the method was valid for nonpregnant measures but questionable in the case of pregnant uterine blood flow. In pregnant sows, the uterine blood flow per kilogram was greatest at 19 days and decreased to a relatively constant rate at 39, 75, and 95 days. Blood flow in the uterine artery was also measured in six late pregnant sows using the electromagnetic flowmeter.