Sequential changes in the concentration of prostaglandins and steroids in uterine lymph in sheep during the oestrous cycle

Sequential samples of uterine lymph were collected from 9 conscious sheep at 4 or 5 h intervals. The mean PGF2 concentration in uterine lymph increased significantly on days 10 and 11 but then fell again, only to increase once more (P less than 0.001) for the 4 days prior to oestrus. PGE2 concentrations in uterine lymph showed no significant changes during the cycle. Lymphatic oestradiol-17 beta concentrations fluctuated throughout the cycle, with peak values considerably higher than those found in peripheral or uterine venous blood.