Weems Y S, Lammoglia M A, Vera-Avila H R, Randel R D, Sasser R G, Weems C W
Department of Animal Sciences, University of Hawaii, Honolulu 96822, USA.
Prostaglandins Other Lipid Mediat. 1998 Apr;55(5-6):359-76. doi: 10.1016/s0090-6980(98)00030-6.
Both Day 14 corpora lutea (CL) of the estrous cycle and Day 200 CL of pregnancy secrete detectable prostaglandin E (PGE) and prostaglandin F2 alpha (PGF2 alpha) in vitro. Corpora lutea from Day 200 pregnant cows secrete more PGE and PGF alpha in vitro than Day 14 CL of the estrous cycle when incubated in control medium without treatments (p < or = 0.05). In addition, secretion of both PGE and PGF2 alpha in vitro by both Day 200 CL of pregnancy and Day 14 of the estrous cycle increase (p < or = 0.05) with time in culture in the absence of treatments. The PGE:PGF2 alpha ratio secreted at 4 h in the absence of treatments by Day 14 CL of the estrous cycle was 1.2 and at 8 h was 1.0 and did not differ (p > or = 0.05), while the PGE:PGF2 alpha ratio secreted by 200 day CL of pregnancy in the absence of treatments at 4 h was 0.8 and at 8 h decreased (p < or = 0.05) to 0.4. The PGE:PGF2 alpha ratio at 8 h by 200 day CL of pregnancy was lower (p < or = 0.05) than in the Day 14 CL of the estrous cycle at 4 or 8 h. Secretion of PGE or PGF2 alpha was affected by luteinizing hormone, PGE2, 8-Epi-PGE1, 8-Epi-PGE2, trichosanthin, and pregnancy specific protein B (PSPB) and was time and dose dependent (p < or = 0.05). In summary, the altered ratio of PGE:PGF2 alpha may explain the decreased secretion of progesterone at 8 h by Day 200 CL of pregnancy reported previously from the same samples. In addition, caution should be exercised in interpretation of progesterone secretion data with bovine CL studies in vitro. Also, PSPB may play an indirect role through PGE to regulate bovine luteal secretion of progesterone.
发情周期第14天的黄体（CL）和妊娠第200天的黄体在体外均能分泌可检测到的前列腺素E（PGE）和前列腺素F2α（PGF2α）。当在未经处理的对照培养基中孵育时，妊娠第200天母牛的黄体在体外分泌的PGE和PGFα比发情周期第14天的黄体更多（p≤0.05）。此外，在未经处理的情况下，妊娠第200天的黄体和发情周期第14天的黄体在体外分泌的PGE和PGF2α均随培养时间增加（p≤0.05）。发情周期第14天的黄体在未经处理时4小时分泌的PGE：PGF2α比值为1.2，8小时为1.0，无差异（p≥0.05），而妊娠第200天的黄体在未经处理时4小时分泌的PGE：PGF2α比值为0.8，8小时时下降（p≤0.05）至0.4。妊娠第200天的黄体在8小时时的PGE：PGF2α比值低于发情周期第14天的黄体在4小时或8小时时的比值（p≤0.05）。PGE或PGF2α的分泌受促黄体生成素、PGE2、8-表-前列腺素E1、8-表-前列腺素E2、天花粉蛋白和妊娠特异性蛋白B（PSPB）的影响，且具有时间和剂量依赖性（p≤0.05）。总之，PGE：PGF2α比值的改变可能解释了先前从相同样本中报道的妊娠第200天的黄体在8小时时孕酮分泌减少的现象。此外，在解释体外牛黄体研究中的孕酮分泌数据时应谨慎。另外，PSPB可能通过PGE间接发挥作用来调节牛黄体孕酮的分泌。
