Vos P L, Bevers M M, Willemse A H, Dieleman S J
Department of Herd Health and Reproduction, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
J Reprod Fertil. 1994 May;101(1):43-9. doi: 10.1530/jrf.0.1010043.
After synchronization of oestrus, normally cyclic heifers (n = 31) received 2500 iu pregnant mares' serum gonadotrophin (PMSG) i.m. and had a progesterone-releasing intravaginal device (PRID) without the oestradiol capsule inserted on day 10 of the oestrous cycle and received 15 mg prostaglandin(PG) i.m. 48 h later. PRIDs were removed 96 h after insertion and 16 heifers received 1.0 mg GnRH i.m. while the controls (n = 15) received 10 ml saline i.m. All heifers were injected with anti-PMSG i.v. 10 later. Peripheral blood concentrations of PMSG, progesterone, oestradiol and LH were compared. Ovaries were collected on death 7 days after the GnRH or saline injection and the number of corpora lutea counted. Heifers were considered to have responded well (> 60 pmol l-1) or poorly (< 60 pmol l-1) to superovulation on the basis of the oestradiol concentration 24 h after PG administration. During PRID treatment, LH concentrations remained at basal values. In the heifers treated with GnRH, a single LH surge occurred 2.3 +/- 0.1 h (SD) after the GnRH injection with a maximum concentration of 14.6 +/- 2.3 (SEM) micrograms l-1 and a duration of 6-8 h. In 12 of the 15 control heifers, LH concentrations remained low (range 0.10-1.94 micrograms l-1) during the 72 h following the saline injection; three controls showed a spontaneous LH surge at 18, 23 and 23 h after the saline injection, respectively, with a maximum concentration of 6.0-12.5 micrograms l-1 and a duration of 10-12 h.(ABSTRACT TRUNCATED AT 250 WORDS)
在发情同期化后，正常发情周期的小母牛（n = 31头）肌肉注射2500国际单位孕马血清促性腺激素（PMSG），并在发情周期第10天放置不含雌二醇胶囊的孕酮释放阴道内装置（PRID），48小时后肌肉注射15毫克前列腺素（PG）。PRID在插入96小时后取出，16头小母牛肌肉注射1.0毫克促性腺激素释放激素（GnRH），而对照组（n = 15头）肌肉注射10毫升生理盐水。10小时后所有小母牛静脉注射抗PMSG。比较PMSG、孕酮、雌二醇和促黄体生成素（LH）的外周血浓度。在GnRH或生理盐水注射7天后处死动物收集卵巢并计数黄体数量。根据PG给药后24小时的雌二醇浓度，将小母牛对超数排卵的反应分为良好（> 60 pmol l-1）或不良（< 60 pmol l-1）。在PRID治疗期间，LH浓度保持在基础值。在用GnRH治疗的小母牛中，GnRH注射后2.3 +/- 0.1小时（标准差）出现单次LH峰，最大浓度为14.6 +/- 2.3（标准误）微克l-1，持续时间为6 - 8小时。在15头对照小母牛中的12头，生理盐水注射后的72小时内LH浓度保持较低水平（范围为0.10 - 1.94微克l-1）；3头对照小母牛分别在生理盐水注射后18、23和23小时出现自发LH峰，最大浓度为6.0 - 12.5微克l-1，持续时间为10 - 12小时。（摘要截断于250字）
