Duong H T, Vu H V, Bah M M, Woclawek-Potocka I, Dam T V, Skarzynski D J, Okuda K, Acosta T J
Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
Reprod Domest Anim. 2012 Apr;47(2):238-43. doi: 10.1111/j.1439-0531.2011.01835.x. Epub 2011 Jul 5.
Prostaglandin F2α (PGF) is considered to be the main luteolysin in cattle. We have previously demonstrated that cortisol (Cr) suppresses PGF production in non-pregnant bovine endometrium. This study was carried out to test whether exogenous PGF increases ovarian and/or uterine PGF production and to determine the temporal relationship between PGF and Cr in ovarian and uterine circulations during PGF-induced luteolysis in cows. Catheters were inserted into the ovarian vein (OV), uterine vein (UV) and jugular vein (JV) of 10 cows on Day 9 of the oestrous cycle (Ovulation = Day 0) for frequent blood collection. On Day 10, the cows were divided randomly into two groups and treated with a luteolytic dose of a PGF analogue (cloprostenol) or saline solution. Blood samples were collected at -0.25, 0, 0.25, 0.5, 1 and 2 h and then at 2-h intervals until 12 h after treatment (0 h). The basal concentrations of PGF and Cr in OV and UV plasma were not significantly different. Injection of a PGF analogue induced more than twofold increases in the levels of PGF between 0.25 and 1 h in UV plasma, but not in OV plasma. PGF increased (p < 0.05) the concentrations of Cr in OV, UV and JV plasma between 0.5 and 1 h. The Cr levels in OV, UV and JV plasma were similar. The PGF levels in UV plasma decreased after Cr reached its highest levels. The overall results suggest that the uterus rather than the ovary increases PGF production in response to PGF injection. Based on the temporal changes of PGF and Cr in the ovarian and uterine circulations, Cr may act to reduce uterine PGF production in non-pregnant cows in vivo.
前列腺素F2α（PGF）被认为是牛体内主要的黄体溶解素。我们之前已经证明，皮质醇（Cr）可抑制未孕牛子宫内膜中PGF的产生。本研究旨在测试外源性PGF是否会增加卵巢和/或子宫的PGF产生，并确定在PGF诱导奶牛黄体溶解过程中，PGF与Cr在卵巢和子宫循环中的时间关系。在发情周期第9天（排卵=第0天），将导管插入10头奶牛的卵巢静脉（OV）、子宫静脉（UV）和颈静脉（JV），以便频繁采血。第10天，将奶牛随机分为两组，分别用黄体溶解剂量的PGF类似物（氯前列醇）或盐溶液进行处理。在处理前-0.25、0、0.25、0.5、1和2小时采集血样，然后在处理后（0小时）以2小时间隔采集血样，直至12小时。OV和UV血浆中PGF和Cr的基础浓度无显著差异。注射PGF类似物使UV血浆中PGF水平在0.25至1小时之间增加了两倍多，但在OV血浆中未增加。PGF使OV、UV和JV血浆中Cr的浓度在0.5至1小时之间增加（p<0.05）。OV、UV和JV血浆中的Cr水平相似。当Cr达到最高水平后，UV血浆中的PGF水平下降。总体结果表明，子宫而非卵巢在注射PGF后会增加PGF的产生。根据PGF和Cr在卵巢和子宫循环中的时间变化，Cr可能在体内作用于降低未孕奶牛子宫中PGF的产生。
