Levels of Prostaglandins in the Uterine Endometrium During the Ovine Estrous Cycle

Abstract
Levels of prostaglandins (PG) F, F and E2 were measured in endometrium from each uterine horn of 35 mature ewes with corpora lutea on only one ovary. After the ewes were killed, the endometria were dissected free, weighed and stored at −20 C. Prostaglandins were extracted, separated by thin layer chromatography and measured by the gerbil-colon bioassay. The percent recovery was determined by using PGF-5,6-3H, and the measured values were corrected to 100%. Ewes in four groups were killed on day 3, 5, 11 or 14 of the estrous cycle, and the mean concentration (ng/g) for both uterine horns of PGF was 32, 60, 76 and 202, and the mean content (ng) was 261, 344, 311 and 1,244, respectively. The levels of PGF at day 14 were different from all other days (P<.05). Ewes in a fifth group received a plastic intra-uterine device (IUD) in each uterine horn at laparotomy on day 2 of the estrous cycle and were killed on day 5. They had a mean concentration (ng/g) and content (ng) for PGF of 179 and 1,050, respectively. The concentration and content of PGF were different from the day 5 control (P<.05). Differences in prostaglandin F levels were not detected between uterine horns adjacent or opposite to a corpus luteum. PGF1 and PGE2 were detectable but often could not be quantified. PGEj was not detected. Copyright © 1972. American Society of Animal Science . Copyright 1972 by American Society of Animal Science