DYNAMICS OF GONADOTROPIN-RELEASING-HORMONE RELEASE DURING A PULSE
DYNAMICS OF GONADOTROPIN-RELEASING-HORMONE RELEASE DURING A PULSE
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DOI：
10.1210/en.130.1.503
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发表时间：
1992-01-01
期刊：
影响因子：
4.8
通讯作者：
KARSCH, FJ
中科院分区：
文献类型：
--
作者：
MOENTER, SM;BRAND, RM;KARSCH, FJ
本研究考察了GnRH信号的性质，该信号沿垂体门静脉传导并引起黄体生成素脉冲。个体GnRH脉冲的增加和减少，幅度，持续时间和GnRH释放量的突然性来描述。从5只短期切除卵巢的母羊身上每隔30秒采集2.5或5小时的垂体门静脉血。每10分钟取一次颈静脉血检测LH。我们检查了13个GnRH脉冲；每个都产生了LH脉冲。大多数GnRH脉冲的轮廓近似于方波。GnRH脉冲的上升沿非常突兀；GnRH分泌在1分钟内增加了50倍。在脉冲期间（24 pg/min，范围2-66）收集的GnRH的平均峰值量是脉冲间基线（0.2-0.5 pg/min）的70倍。释放时间平均持续5.5 min；此后，GnRH在3分钟内降至脉冲前水平。总的来说，更大和更长的GnRH脉冲与更高振幅的LH脉冲相关。为了评估收集过程中GnRH信号的失真，通过注射泵在体外使用相同的技术在施加4和7分钟方波GnRH脉冲期间获得样品。信号作为方波通过采样操作进行，失真最小，除了在采集过程中幅度下降。我们的研究结果表明，在体内观察到的方波脉冲是短期卵巢切除母羊脉冲期间GnRH释放动态的准确描述。
This study examined the nature of the GnRH signal that travels down the pituitary portal vessels and causes an LH pulse. Individual GnRH pulses were described in terms of abruptness of increase and decrease, amplitude, duration, and amount of GnRH released. Pituitary portal blood was obtained at 30-sec intervals for 2.5 or 5 h from five short-term ovariectomized ewes. Jugular blood was sampled every 10 min for LH. We examined 13 GnRH pulses; each produced an LH pulse. The contour of most GnRH pulses approximated a square wave. The rising edge of the GnRH pulse was very abrupt; GnRH secretion increased as much as 50-fold within 1 min. The mean peak amount of GnRH collected during pulses (24 pg/min, range 2-66) was 70-fold greater than the interpulse baseline (0.2-0.5 pg/min). The release period was sustained an average of 5.5 min; thereafter, GnRH fell to prepulse levels within 3 min. Overall, the larger and more prolonged pulses of GnRH were associated with higher amplitude LH pulses. To assess the distortion of the GnRH signal by the collection procedure, samples were obtained in vitro using the same technique during application of 4- and 7-min square wave GnRH pulses by means of a syringe pump. Signals were carried as square-waves through the sampling operation with minimal distortion, with the exception that amplitude decreased during the collection procedure. Our findings indicate the square-wave pulses observed in vivo are an accurate description of the dynamics of GnRH release during a pulse in short-term ovariectomized ewes.