Takahashi M, Ford J J, Yoshinaga K, Greep R O
Endocrinology. 1975 Feb;96(2):453-7. doi: 10.1210/endo-96-2-453.
Hypothalamic content of LHRH was radioimmunoassayed after cervical stimulation on the morning of day of estrus' LHRH content rose 3-fold by 120 min after the stimulation, reaching a level equivalent to that of day 5 of pseudopregnancy. The increase was not steady as there were two early periods when the content did not increase. Measurement of pituitary LH content revealed a marked increase followed by a sudden decrease which corresponded respectively to the two periods when LHRH levels failed ro tise. These changes in pituitary LH level suggest that both the synthesis and release of LH in the pituitary are promoted by the action of LHRH released from the hypothalamus. LH changes in the pituitary were abolished iv injection of 2 ml LHRH antiserum at the time of cervical stimulation, but pseudopregnancy was still induced and diestrus prolonged 4 days longer than in the control group. Progestin concentrations in ovarian vein blood were comparable between anti-LHRH-treated and control groups. These results suggest that the LH released by cervical stimulation is dispensable for the induction of pseudopregnancy. The marked elevation of LHRH in the hypothalamus observed immediately after cervical stimulation must be related to the regulatory mechanism of the characteristic secretory pattern of LH during the period of pseudopregnancy.
在发情日早晨进行宫颈刺激后，对下丘脑促黄体激素释放激素（LHRH）含量进行放射免疫测定。刺激后120分钟，LHRH含量增加了3倍，达到与假孕第5天相当的水平。增加并不稳定，因为有两个早期阶段含量没有增加。垂体促黄体生成素（LH）含量测定显示，先是显著增加，随后突然下降，这分别与LHRH水平未能上升的两个时期相对应。垂体LH水平的这些变化表明，下丘脑释放的LHRH的作用促进了垂体中LH的合成和释放。在宫颈刺激时静脉注射2毫升LHRH抗血清可消除垂体中的LH变化，但仍能诱导假孕，且间情期比对照组延长4天。抗LHRH处理组和对照组卵巢静脉血中的孕激素浓度相当。这些结果表明，宫颈刺激释放的LH对于诱导假孕并非必需。宫颈刺激后立即观察到的下丘脑LHRH的显著升高一定与假孕期间LH特征性分泌模式的调节机制有关。
