Metabolism of arachidonic acid in vitro by ovine conceptuses recovered during early pregnancy |
| |
Authors: | GS Lewis RA Waterman |
| |
Institution: | Reproduction Laboratory Animal Science Institute U.S. Department of Agriculture Beltsville, Maryland 20707 USA |
| |
Abstract: | Metabolism of 3H] arachidonic acid (3H] AA) and synthesis of prostaglandins were examined with ovine conceptuses and endometrial slices collected on various days after mating. Tissues were incubated for 24 hr with or without 5 μCi of 3H] AA and with 200 μg radioinert AA. In experiment 1, results of chromatography indicated that conceptuses collected on days 14 and 16 after mating metabolized 3H] AA to PGE2, PGF2α, PGFM, 6-keto-PGF1α, and to unidentified compounds in three chromatographic regions. One of these regions (region 1) contained triglycerides. Endometrial slices metabolized only small amounts of the 3H] AA to prostaglandins. In experiment 2, results of radioimmunoassays indicated that day 14 conceptuses released somewhat similar amounts (ng/mg tissue) of PGF2α (32.1 ± 17.9), PGFM (8.4 ± 6.2), PGE2 (12.3 ± 7.5) and 6-keto-PGF1α (41.4± 4.8), whereas day 16 conceptuses released more (P<.05) PGF2α (9.0 ± 4.1) and 6-keto-PGF1α (15.9 ± 2.7) than PGE2 (0.9 ± 0.2) or PGFM (0.5 ± 0.08). Day 14 and 16 endometrial slices released (ng/mg tissue) more (P<.05) PGFM (3.0 ± 0.2) and 6-keto-PGF1α (4.0 ± 0.4) than PGF2α (0.5 ± 0.08) or PGE2 (0.05 ± 0.02). In experiment 3, conceptuses were recovered on days 16, 20 and 24 of pregnancy and incubated with 3H] AA to determine the effects of indomethacin on 3H] AA metabolism. In general, indomethacin (Id; 4 × 10−4 M) reduced (P<.05) the percentage of total dpm recovered as prostaglandins, but Id increased the release of chromatographic region I. Experiment 4 was conducted with day 16, 20 and 24 conceptuses to evaluate the time course of metabolism of 3H] AA, and the appearance of region I and of prostaglandins. In general, the percentage of total dpm in region I increased as the percentage of dpm as 3H] AA decreased. The percentage of dpm as prostaglandins increased as the percentage of dpm in region I decreased. Prostaglandins, probably essential for embroynal survival and development, were synthesized in vitro by ovine conceptuses. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|