Khorram O, Pau K Y, Spies H G
Reproductive Biology and Behavior, Oregon Regional Primate Research Center, Beaverton 97006.
Peptides. 1988 Mar-Apr;9(2):411-7. doi: 10.1016/0196-9781(88)90277-x.
The effect of NPY on the hypothalamic release of GnRH and pituitary release of gonadotropins was examined in intact and ovariectomized (OVEX) rabbits in a superfusion system. Exposure of mediobasal hypothalami (MBH) from intact rabbits to NPY (8 X 10(-8) M) resulted in a sustained stimulation of GnRH secretion into the medium. The same dose of NPY had no effect on MBH-GnRH release from OVEX rabbits. NPY also produced a sustained stimulation of LH and FSH release by pituitary fragments from intact rabbits, but NPY caused only a transient release of these hormones by pituitaries from OVEX does. Media samples from MBH superfusions were also measured for NPY concentrations. NPY was released episodically into the medium. The amplitude and frequency of NPY pulses in intact and OVEX rabbits did not differ; nor were mean levels of NPY significantly affected by castration. These results suggest that NPY has direct effects on both the hypothalamus and pituitary to modulate the the activities of GnRH neurons and gonadotropes. The pattern of GnRH and gonadotropin response to NPY exposure is determined by ovarian factors.
在一个灌流系统中，研究了神经肽Y（NPY）对完整和去卵巢（OVEX）家兔下丘脑促性腺激素释放激素（GnRH）释放及垂体促性腺激素释放的影响。将完整家兔的中基底下丘脑（MBH）暴露于NPY（8×10⁻⁸M），可导致GnRH持续分泌到培养基中。相同剂量的NPY对去卵巢家兔的MBH-GnRH释放没有影响。NPY还能持续刺激完整家兔垂体碎片释放促黄体生成素（LH）和促卵泡生成素（FSH），但NPY只能使去卵巢母兔垂体短暂释放这些激素。还检测了MBH灌流的培养基样本中的NPY浓度。NPY呈间歇性释放到培养基中。完整和去卵巢家兔中NPY脉冲的幅度和频率没有差异；去势也未显著影响NPY的平均水平。这些结果表明，NPY对下丘脑和垂体都有直接作用，可调节GnRH神经元和促性腺激素细胞的活性。GnRH和促性腺激素对NPY暴露的反应模式由卵巢因素决定。
