Brito L F C, Baldrighi J M, Wolf C A, Ginther O J
Eutheria Foundation, Cross Plains, WI, 53528, USA.
Eutheria Foundation, Cross Plains, WI, 53528, USA; Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Anim Reprod Sci. 2017 Jan;176:64-69. doi: 10.1016/j.anireprosci.2016.11.010. Epub 2016 Nov 23.
The objective of the present study was to investigate the effect of reproductive hormones (GnRH, hCG, LH and progesterone) on the regulation of corpus luteum (CL) and ovarian blood flow. Diestrous mares received a single treatment of saline, 100μg gonadorelin (GnRH), or 1500IU hCG 10days after ovulation. Plasma LH and progesterone concentrations, resistance index (RI) for ovarian artery blood-flow, and percentage of corpus luteum (CL) with color-Doppler signals of blood flow were determined immediately before treatment (hour 0) and at hours 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, and 6. In the GnRH group, LH increased (P<0.0001) between hours 0 and 0.25 and then progressively decreased; concentration of LH was not affected in the saline and hCG groups. Progesterone concentration was not different among groups. In the GnRH group, RI tended (P<0.07) to decrease between hours 0 and 1.5 and increased (P<0.01) between hours 1.5 and 4. In the hCG group, two transient RI decreases (P<0.05) occurred before hour 2. The percentage change from hour 0 in the percentage of CL with blood-flow signals was greater at hour 0.5 in the GnRH group than in the saline group and was intermediate in the hCG group. The similarity among groups in progesterone concentration indicated that changes in progesterone were not involved in the GnRH and hCG stimulation of ovarian vascular perfusion. Effects of treatment might have been mediated through LH; however, since hCG biological activity is primarily LH-like, the differences in timing and degree of ovarian and luteal blood flow changes after GnRH or hCG administration in the present study suggest that GnRH might have a direct effect on ovarian blood vessels and vascular control.
本研究的目的是探讨生殖激素（促性腺激素释放激素、人绒毛膜促性腺激素、促黄体生成素和孕酮）对黄体（CL）调节及卵巢血流的影响。在间情期母马排卵后10天，分别给予生理盐水、100μg促性腺激素释放激素（GnRH）或1500IU人绒毛膜促性腺激素（hCG）单次处理。在处理前（0小时）以及处理后0.25、0.5、1、1.5、2、3、4、5和6小时，测定血浆促黄体生成素和孕酮浓度、卵巢动脉血流阻力指数（RI）以及有血流彩色多普勒信号的黄体（CL）百分比。在GnRH组，促黄体生成素在0至0.25小时之间升高（P<0.0001），然后逐渐下降；生理盐水组和hCG组促黄体生成素浓度未受影响。各组孕酮浓度无差异。在GnRH组，RI在0至1.5小时之间有下降趋势（P<0.07），在1.5至4小时之间升高（P<0.01）。在hCG组，在2小时之前出现两次短暂的RI下降（P<0.05）。GnRH组在0.5小时时有血流信号的CL百分比相对于0小时的变化百分比大于生理盐水组，hCG组则介于两者之间。各组孕酮浓度相似，表明孕酮变化不参与GnRH和hCG对卵巢血管灌注的刺激。处理效果可能是通过促黄体生成素介导的；然而，由于hCG的生物活性主要类似于促黄体生成素，本研究中GnRH或hCG给药后卵巢和黄体血流变化的时间和程度差异表明，GnRH可能对卵巢血管和血管调控有直接作用。
