Garcia M C, Ginther O J
Am J Vet Res. 1975 Nov;36(11):1581-4.
Three experiments were performed to study the luteinizing hormone (LH) and ovulatory responses to various doses and methods of administration of gonadotropin-releasing hormone (GnRH) in estrous pony mares and the influence of estradiol-17beta (E2-17beta) on LH response to GnRH treatment. In experiment 1, single injections of synthetic GnRH were subcutaneously given to 5 groups of estrous (day 2) mares (3 mares/group) on a body weight basis as follows: group A--isotonic saline solution; group B--GnRH, 0.14 mug/kg; group C--GnRH, 0.28 mug/kg; group D--KGnRH, 0.59 mug/kg; and group E--GnRH, 2.37 mug/kg. Significant increase of plasma LH concentration lasting for approximately 2 hours occurred only in mares of group E given the largest dose of GnRH (2.37 mug/kg). Plasma LH concentration increase at 1 hour after treatment approached significane (P less than 0.10) in mares of group D given the next smaller dose. In experiment 2, GnRH (2.37 mug/kg) was intravenously infused for 24 hours to a group of 6 mares (group F); 6 other mares (group G) were given saline solution infusion. Mean plasma LH concentration was increased at 3 hours, continued to increase until 6 hours, and remained at approximately the 6-hour concentration throughout the period of GnRH infusion. In the 3rd experiment, 3 groups of mares (4 mares/group) were subcutaneously given the following treatments on days 2 and 3 of estrus, respectively: group H--corn oil and saline solution; group I--corn oil and GnRH, 0.59 mug/kg; and group J--estradiol-17beta, 0.5 mg, and GnRH, 0.59 mug/kg. Plasma LH response was not seen in group H mares given corn oil and saline solution. Mean plasma LH concentration at 1 hour after administration of GnRH approached significance (P less than 0.10) in group I mares given corn oil and GnRH. For the mares in group J given E2-17beta and GnRH, E2-17beta pretreatment increased plasma LH after 24 horus; significnat increases of plasma LH concentration were seen from 1 to 6 hours after GnRH injection. None of the treatments in experiments 1, 2, and 3 significantly altered the time of ovulation.
进行了三项实验，以研究在发情期母马中促黄体生成素（LH）以及对不同剂量和给药方法的促性腺激素释放激素（GnRH）的排卵反应，以及雌二醇-17β（E2-17β）对LH对GnRH治疗反应的影响。在实验1中，按照体重对5组发情期（第2天）母马（每组3匹）皮下注射合成GnRH，具体如下：A组——等渗盐溶液；B组——GnRH，0.14微克/千克；C组——GnRH，0.28微克/千克；D组——GnRH，0.59微克/千克；E组——GnRH，2.37微克/千克。仅在给予最大剂量GnRH（2.37微克/千克）的E组母马中，血浆LH浓度出现了持续约2小时的显著升高。给予次小剂量的D组母马在治疗后1小时血浆LH浓度升高接近显著水平（P<0.10）。在实验2中，对一组6匹母马（F组）静脉输注GnRH（2.37微克/千克）24小时；另外6匹母马（G组）输注盐溶液。平均血浆LH浓度在3小时时升高，持续升高直至6小时，并在整个GnRH输注期间维持在大约6小时时的浓度。在第三个实验中，分别在发情期的第2天和第3天对3组母马（每组4匹）皮下给予以下处理：H组——玉米油和盐溶液；I组——玉米油和GnRH，0.59微克/千克；J组——雌二醇-17β，0.5毫克，和GnRH，0.59微克/千克。给予玉米油和盐溶液的H组母马未出现血浆LH反应。给予玉米油和GnRH的I组母马在GnRH给药后1小时平均血浆LH浓度接近显著水平（P<0.10）。对于给予E2-17β和GnRH的J组母马，E2-17β预处理在24小时后增加了血浆LH；在GnRH注射后1至6小时观察到血浆LH浓度显著升高。实验1、2和3中的任何处理均未显著改变排卵时间。
