Tabarelli M, Kofler R, Berger P, Wick G
J Reprod Immunol. 1982 Dec;4(6):325-35. doi: 10.1016/0165-0378(82)90007-9.
In vivo experiments showed that anti-bovine luteinizing hormone rabbit serum (a-LH) reversed the abortifacient effect of Bromergocryptine (BEC) on day 6 of pregnancy in 13 of 19 rats when injected 5-15 h after the initial BEC administration. Radioreceptor assay studies revealed that BEC treatment entailed an 85% drop of ovarian LH-receptor (LH-rec) concentration and a drastic decrease in progesterone serum levels. a-LH restored both the ovarian LH-rec content and progesterone serum levels in those rats that were found to have macroscopically intact implantations. A time course study of LH serum levels after BEC treatment showed a trend for BEC to stimulate LH secretion with a maximum 12-18 h after the initial BEC injection. These experiments indicate that (i) BEC terminates early rat pregnancy primarily by inducing a process of desensitization of ovarian LH-rec by blocking prolactin (PRL) secretion and possibly also by additionally stimulating LH secretion, which in the absence of endogenous PRL causes HL-rec and serum progesterone levels to drop; (ii) a-LH administration without simultaneous PRL substitution may rescue LH-rec of BEC treated rats from being desensitized as well as prevent fetuses from being resorbed. It is suggested that the contribution of PRL in the luteotropic complex is permissive for the luteotropic action of LH and/or for keeping the corpus luteum in a functional state rather than being luteotropic by itself.
体内实验表明，在首次注射溴隐亭（BEC）后5 - 15小时注射抗牛促黄体激素兔血清（a - LH），可使19只大鼠中的13只在妊娠第6天逆转BEC的堕胎作用。放射受体分析研究显示，BEC处理导致卵巢促黄体激素受体（LH - rec）浓度下降85%，血清孕酮水平急剧降低。a - LH可使那些经肉眼观察植入物完整的大鼠的卵巢LH - rec含量和血清孕酮水平恢复正常。对BEC处理后促黄体激素血清水平的时间进程研究表明，BEC有刺激促黄体激素分泌的趋势，在首次注射BEC后12 - 18小时达到最大值。这些实验表明：（i）BEC主要通过阻断催乳素（PRL）分泌诱导卵巢LH - rec脱敏过程，并可能还通过额外刺激促黄体激素分泌来终止大鼠早期妊娠，在缺乏内源性PRL的情况下，这会导致HL - rec和血清孕酮水平下降；（ii）在没有同时替代PRL的情况下给予a - LH，可使BEC处理的大鼠的LH - rec免于脱敏，并防止胎儿被吸收。提示催乳素在促黄体复合物中的作用是允许促黄体激素发挥促黄体作用和/或将黄体维持在功能状态，而不是其本身具有促黄体作用。
