Endometrial blood flow in rats

The endometrial blood flow was measured in rats by injections of 85Kr saline into aorta and measurements of the clearance of the radioactivity by a Geiger-Müller probe situated in the uterine lumen. Estrus and diestrus were determined by vaginal smears. The endometrial blood flow was found to be 0.88 +/- 0.08 (mean +/- SEM) ml/g tissue/min in estus and 1.60 +/- 0.15 mg/g/min in diestrus. The experiment indicates that the endometrial blood flow and the total uterine blood flow change in opposite directions during the estrous cycle.