Clarke I J, Cummins J T
J Reprod Fertil. 1985 Mar;73(2):425-31. doi: 10.1530/jrf.0.0730425.
We have measured the size of the releasable pools of LH and FSH in the pituitary glands of ovariectomized ewes in which the pituitary was isolated surgically from the hypothalamus. The ewes were given GnRH pulses (250 ng) every hour (N = 3) or every 2 h (N = 3) for 1 week and then given a high dose GnRH infusion (0.5 micrograms/min) for 4 h. Blood samples were collected to characterize the LH and FSH responses to the GnRH pulses and infusion. The LH, but not FSH, responses to the individual GnRH pulses were pulsatile and the amplitudes of the LH pulses were greater in the sheep receiving pulses every 2 h. The sheep receiving hourly pulses showed lower LH responses to the high-dose infusions than did the sheep receiving pulses every 2 h. These data indicate a relationship between the amplitude of LH pulses and the size of the releasable pool of LH in the pituitary gland. As the frequency of GnRH pulses is decreased the amplitude of the LH responses is increased in direct proportion to the size of the releasable LH pool.
我们测量了手术分离垂体与下丘脑的去卵巢母羊垂体中促黄体生成素（LH）和促卵泡生成素（FSH）可释放池的大小。这些母羊每小时（N = 3）或每2小时（N = 3）接受一次促性腺激素释放激素（GnRH）脉冲（250 ng），持续1周，然后接受4小时的高剂量GnRH输注（0.5微克/分钟）。采集血样以表征LH和FSH对GnRH脉冲和输注的反应。对单个GnRH脉冲的LH反应（而非FSH反应）呈脉冲式，且每2小时接受一次脉冲的绵羊中LH脉冲的幅度更大。每小时接受一次脉冲的绵羊对高剂量输注的LH反应低于每2小时接受一次脉冲的绵羊。这些数据表明LH脉冲幅度与垂体中LH可释放池大小之间存在关联。随着GnRH脉冲频率降低，LH反应幅度与可释放LH池大小成正比增加。
