Peters A R
Research Group on Hormones and Farm Animal Reproduction, University of Nottingham, Faculty of Agricultural Science, Loughborough, Leicestershire.
Vet Rec. 1989 Apr 8;124(14):371-3. doi: 10.1136/vr.124.14.371.
This study was designed to evaluate the effects of exogenous prostaglandin F2 alpha (PGF2 alpha) on hormone secretion in cows without a corpus luteum. Blood samples were taken from 10 Friesian dairy cows at frequent intervals from a jugular vein and the caudal vena cava starting between nine and 20 days after parturition. PGF2 alpha (25 mg dinoprost) was injected intramuscularly into five cows after the first eight hours of sampling. Plasma concentrations of 13,14-dihydro 15-keto PGF2 alpha (PGFM) increased rapidly but had returned to baseline by 14 hours after injection. There was no significant effect of the treatment on the time taken by the cows to resume ovarian cycles, and it had no consistent effect on plasma luteinising hormone (LH) patterns; however the amplitude of pulses of LH was temporarily suppressed in two cows and the frequency of pulses of LH was immediately increased in one cow. Treatment with PGF2 alpha had no significant effect on the concentration of oestradiol in blood from the vena cava. It is concluded that any enhancement of the reproductive performance of cows treated with PGF2 alpha after parturition is not due to a direct effect on pituitary-ovarian function.
本研究旨在评估外源性前列腺素F2α（PGF2α）对无黄体奶牛激素分泌的影响。在产后9至20天之间，从10头弗里生奶牛的颈静脉和尾腔静脉频繁采集血样。在采样的前8小时后，对5头奶牛进行肌肉注射PGF2α（25毫克氯前列醇）。血浆中13,14-二氢15-酮PGF2α（PGFM）的浓度迅速升高，但在注射后14小时恢复到基线水平。该处理对奶牛恢复卵巢周期所需的时间没有显著影响，并且对血浆促黄体生成素（LH）模式没有一致的影响；然而，有两头奶牛的LH脉冲幅度暂时受到抑制，一头奶牛的LH脉冲频率立即增加。PGF2α处理对尾腔静脉血中雌二醇的浓度没有显著影响。得出的结论是，产后用PGF2α处理的奶牛生殖性能的任何提高并非由于对垂体-卵巢功能的直接作用。
