交配诱导促黄体生成素激增期间，兔中基底部和下丘脑前部促性腺激素释放激素和去甲肾上腺素的释放

Gonadotropin-releasing hormone and norepinephrine release from the rabbit mediobasal and anterior hypothalamus during the mating-induced luteinizing hormone surge.

作者信息

Kaynard A H, Pau K Y, Hess D L, Spies H G

机构信息

Division of Reproductive Biology and Behavior, Oregon Regional Primate Research Center, Beaverton 97006.

出版信息

Endocrinology. 1990 Sep;127(3):1176-85. doi: 10.1210/endo-127-3-1176.

DOI:10.1210/endo-127-3-1176

PMID:2117523

Abstract

The release of hypothalamic GnRH in association with the mating-induced LH surge was studied in the rabbit. Push-pull perfusion (PPP) of the mediobasal (MBH) or anterior (AH) regions of the hypothalamus was performed on conscious, unrestrained does for 3 h before and 5 h after exposure to a vasectomized buck. In experiment 1, GnRH concentrations were measured by RIA in 20-min fractions of MBH-PPP. An approximately 100-fold increase in GnRH release was observed within 1 h of coitus (pre, 1.15 +/- 0.29 pg/ml; peak, 106.67 +/- 37.42 pg/ml; n = 6; P less than 0.05). Concomitant surges of LH and PRL in the peripheral circulation were observed. In experiment 2, GnRH and norepinephrine (NE) were measured (the latter by radioenzymatic assay) in 10-min fractions of MBH-PPP. A 218% postcoital rise in NE levels (n = 5; P less than 0.05) in MBH-PPP accompanied an approximately 50-fold peak rise in GnRH in the same samples (pre, 1.57 +/- 0.23 pg/ml; peak, 76.52 +/- 50.14 pg/ml; P less than 0.05). MBH-NE, MBH-GnRH, LH, and PRL release began rising within 10 min of coitus. In experiment 3, GnRH was measured in 20 min fractions of AH-PPP. Coitus induced a marked rise in AH-GnRH release (precoitus, 0.31 +/- 0.03 pg/ml; peak, 2.25 +/- 0.80 pg/ml; n = 4; P less than 0.05) which differed from coitus-induced MBH-GnRH release both quantitatively (i.e. approximately 7-fold increase for AH vs. approximately 50-100-fold increase for MBH; 50-min lag time for AH vs. less than 20 min for MBH) and qualitatively (i.e. AH-GnRH release was discontinuous, while MBH-GnRH release rose sharply, plateaued, and then declined slowly over the 2-5 h following coitus). No changes in MBH-NE, MBH-GnRH, AH-GnRH, LH, FSH, or PRL were observed in sham-mated does (Exp 1, n = 7; Exp 2, n = 3; Exp 3, n = 4). These data support the hypotheses that: 1) hypothalamic GnRH release is a component of reflexive ovulation in the rabbit; 2) increased hypothalamic noradrenergic tone is related to the surge-release of GnRH; and 3) AH-GnRH release is enhanced following coitus.

摘要

本研究在兔中探讨了与交配诱导的促黄体生成素（LH）激增相关的下丘脑促性腺激素释放激素（GnRH）的释放情况。在暴露于输精管结扎的雄兔之前3小时和之后5小时，对清醒、未受束缚的雌兔进行下丘脑中间基底部（MBH）或前部（AH）区域的推挽式灌注（PPP）。在实验1中，通过放射免疫分析法（RIA）在MBH-PPP的20分钟样本中测量GnRH浓度。在交配后1小时内观察到GnRH释放增加了约100倍（性交前，1.15±0.29 pg/ml；峰值，106.67±37.42 pg/ml；n = 6；P<0.05）。同时观察到外周循环中LH和催乳素（PRL）的激增。在实验2中，在MBH-PPP的10分钟样本中测量GnRH和去甲肾上腺素（NE）（后者通过放射酶法测定）。MBH-PPP中NE水平在性交后升高218%（n = 5；P<0.05），同时同一样本中GnRH峰值升高约50倍（性交前，1.57±0.23 pg/ml；峰值，76.52±50.14 pg/ml；P<0.05）。MBH-NE、MBH-GnRH、LH和PRL释放在交配后10分钟内开始上升。在实验3中，在AH-PPP的20分钟样本中测量GnRH。性交诱导AH-GnRH释放显著增加（性交前，0.31±0.03 pg/ml；峰值，2.25±0.80 pg/ml；n = 4；P<0.05），其在数量上（即AH增加约7倍，而MBH增加约50 - 100倍；AH滞后50分钟，而MBH少于20分钟）和质量上（即AH-GnRH释放是不连续的，而MBH-GnRH释放在性交后2 - 5小时内急剧上升、达到平台期，然后缓慢下降）均与性交诱导的MBH-GnRH释放不同。在假交配的雌兔中未观察到MBH-NE、MBH-GnRH、AH-GnRH、LH、卵泡刺激素（FSH）或PRL的变化（实验1，n = 7；实验2，n = 3；实验3，n = 4）。这些数据支持以下假设：1）下丘脑GnRH释放是兔反射性排卵的一个组成部分；2）下丘脑去甲肾上腺素能张力增加与GnRH的激增释放有关；3）性交后AH-GnRH释放增强。