MacDonald R D, Page R D
J Dairy Sci. 1986 Jul;69(7):1922-31. doi: 10.3168/jds.S0022-0302(86)80619-1.
The effects of 12 hourly 5-micrograms injections of luteinizing hormone-releasing hormone on luteinizing hormone release, were examined in 18 prepubertal Holstein heifers at 4, 7, or 10 mo of age. During a 6-h pretreatment period, mean serum luteinizing hormone concentrations and mean number of endogenous luteinizing hormone episodes per hour were not influenced by age. The 12-h treatment regimen induced a pulsatile release of luteinizing hormone in all heifers. The magnitude, pattern, and total amount of luteinizing hormone released were not influenced by age. However, in the 4 and 10-mo-old age groups, magnitude of luteinizing hormone response to the 3rd hourly injection of luteinizing hormone-releasing hormone was greater than the response to the second injection. Magnitudes of luteinizing hormone responses decreased with time after the 4th hourly injection through the 12th injection and patterns of decline appeared similar among the three age groups. The pituitary of the prepubertal dairy heifer is able to respond to an hourly pulsatile administration of luteinizing hormone-releasing hormone and this treatment regimen appears to produce a self-priming effect on luteinizing hormone release.
对18头4、7或10月龄的青春期前荷斯坦小母牛，研究了每12小时注射5微克促黄体生成激素释放激素对促黄体生成激素释放的影响。在6小时的预处理期内，平均血清促黄体生成激素浓度和每小时内源性促黄体生成激素脉冲的平均次数不受年龄影响。12小时的治疗方案在所有小母牛中均诱导了促黄体生成激素的脉冲式释放。促黄体生成激素释放的幅度、模式和总量不受年龄影响。然而，在4月龄和10月龄年龄组中，每小时第三次注射促黄体生成激素释放激素时促黄体生成激素的反应幅度大于第二次注射时的反应。从每小时第四次注射到第十二次注射后，促黄体生成激素反应的幅度随时间下降，且三个年龄组中下降模式相似。青春期前奶牛小母牛的垂体能够对每小时脉冲式给予促黄体生成激素释放激素产生反应，并且这种治疗方案似乎对促黄体生成激素释放产生了自我启动效应。
