Skidmore J A, Starbuck G R, Lamming G E, Allen W R
Camel Reproduction Centre, Dubai, UAE.
J Reprod Fertil. 1998 Nov;114(2):201-9. doi: 10.1530/jrf.0.1140201.
Blood plasma concentrations of 13,14-dihydro-15-keto PGF2 alpha (PGFM) were measured in groups of mature non-pregnant and pregnant camels to study PGF2 alpha release patterns around the time of luteolysis and the timing of the signal for pregnancy recognition. Injection of each of four camels with 10 and 50 mg of PGF2 alpha showed clearly that five times the dose of exogenous hormone produced five times the amount of PGFM in peripheral plasma, thereby indicating that, as in other animal species, PGFM is the principal metabolite of PGF2 alpha in the camel. Serial sampling of three non-pregnant camels on each of days 8, 10 and 12, and three pregnant camels on day 10, after ovulation for 8 h showed a significant (P < 0.05) rise in mean plasma PGFM concentrations only on day 10 in the non-pregnant, but not the pregnant, animals. A single intravenous injection of 20, 50 or 100 iu oxytocin given to three groups of three non-pregnant camels on day 10 after ovulation did not increase their basal serum PGFM concentrations. However, daily treatment of six non-pregnant camels between days 6 and 15 (n = 3) or 20 (n = 3) after ovulation with 1-2 g of the prostaglandin synthetase inhibitor, meclofenamic acid, inhibited PGF2 alpha release and thereby resulted in continued progesterone secretion throughout the period of meclofenamic acid administration. These results showed that, as in other large domestic animal species, release of PGF2 alpha from, presumably, the endometrium controls luteolysis in the dromedary camel. Furthermore, reduction in the amount of PGF2 alpha released is associated with luteal maintenance and the embryonic signal for maternal recognition of pregnancy must be transmitted before day 10 after ovulation if luteostasis is to be achieved. However, the results also indicate that, in contrast to ruminants, the release of endometrial PGF2 alpha in the non-pregnant camel may not be controlled by the release of oxytocin.
测定了成年未孕和怀孕骆驼群体血浆中13,14-二氢-15-酮前列地尔F2α（PGFM）的浓度，以研究黄体溶解前后PGF2α的释放模式以及妊娠识别信号的时间。给4头骆驼分别注射10毫克和50毫克PGF2α，结果清楚显示，外源性激素剂量增加5倍，外周血浆中PGFM的量也增加5倍，这表明，与其他动物物种一样，PGFM是骆驼体内PGF2α的主要代谢产物。对3头未孕骆驼在排卵后第8、10和12天每天进行连续采样，对3头怀孕骆驼在排卵后第10天采样，采样持续8小时，结果显示，仅在未孕动物的第10天，平均血浆PGFM浓度出现显著（P<0.05）升高，而怀孕动物未出现升高。在排卵后第10天，给3组各3头未孕骆驼分别静脉注射20、50或100国际单位催产素，未使其基础血清PGFM浓度升高。然而，在排卵后第6至15天（n = 3）或第20天（n = 3），用1-2克前列腺素合成酶抑制剂甲氯芬那酸对6头未孕骆驼进行每日治疗，抑制了PGF2α的释放，从而在整个甲氯芬那酸给药期间导致孕酮持续分泌。这些结果表明，与其他大型家畜物种一样，推测来自子宫内膜的PGF2α释放控制着单峰驼的黄体溶解。此外，PGF2α释放量的减少与黄体维持有关，如果要实现黄体静止，母体识别妊娠的胚胎信号必须在排卵后第10天之前传递。然而，结果还表明，与反刍动物不同，未孕骆驼子宫内膜PGF2α的释放可能不受催产素释放的控制。
