Effects of neuropeptide Y on the in vitro release of gonadotropin-releasing hormone, luteinizing hormone, and beta-endorphin and pituitary responsiveness to gonadotropin-releasing hormone in female macaques.
Effects of neuropeptide Y on the in vitro release of gonadotropin-releasing hormone, luteinizing hormone, and beta-endorphin and pituitary responsiveness to gonadotropin-releasing hormone in female macaques.
复制标题
神经肽 Y 对雌性猕猴体外促性腺激素释放激素、黄体生成素和 β-内啡肽释放以及垂体对促性腺激素释放激素反应性的影响。
DOI：
10.1159/000125747
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发表时间：
1991
影响因子：
4.1
通讯作者：
Spies,HG
中科院分区：
文献类型：
--
作者：
Pau,KY;Kaynard,AH;Hess,DL;Spies,HG
这些研究的目的是检测神经肽Y（NPY）处理对猕猴下丘脑促性腺激素释放激素（GnRH）和β-内啡肽样活性（β-EP）的释放以及猕猴垂体前叶促黄体生成激素（LH）和GnRH诱导的LH的释放的反应。将下丘脑前（AH）和下丘脑中基底（MBH）组织块和腺垂体沿中线沿着分为两个相等大小的片段。将片段用培养基灌流3小时，然后用NPY（80 nM）或单独的培养基灌流3小时。在一个单独的实验中，腺垂体（AP）片段按照相同的方案（3小时培养基- 3小时NPY或培养基）进行灌流，不同的是在第3小时开始时加入外源性GnRH（352 nM）30分钟，并在第6小时开始时再次加入。在每隔10分钟收集的灌流液样本（400 µl）中测量免疫活性GnRH、β-EP和LH水平。GnRH水平在开始NPY治疗的20-30分钟内升高，并且在来自卵巢完整（INT）恒河猴（Macaca mulatta; n = 8; p < 0.05）或日本（Macaca fascicularis; n = 4; p < 0.01）恒河猴的AH和MBH片段的NPY暴露期间，GnRH释放升高持续。NPY处理对从卵巢切除（OVX）恒河猴分离的AH或MBH片段没有影响（AH为n = 4，MBH为n = 5）。在从INT恒河猴（n = 8）分离的AP片段中，NPY在处理1小时内刺激LH释放（p < 0.05），而NPY对OVX动物的垂体没有影响（n = 4）。外源性GnRH在20分钟内刺激LH释放;然而，给予NPY并不改变日本猕猴垂体对GnRH的反应性（p > 0.05; n = 7）。NPY处理对INT或OVX恒河猴AH、MBH和AP组织中β-EP的释放没有影响。这些结果提示：（1）NPY刺激猕猴下丘脑GnRH释放和垂体前叶LH释放的作用需要卵巢功能正常;（2）NPY不增强猕猴促性腺激素对GnRH刺激的敏感性;（3）NPY刺激猕猴下丘脑GnRH释放和垂体前叶LH释放的作用机制可能不涉及β-EP的神经元释放。
The objectives of these studies were to examine the release of gonadotropin-releasing hormone (GnRH) and β-endorphin-like activity (β-EP) from macaque hypothalami, and the release of luteinizing hormone (LH) and GnRH-induced LH from macaque anterior pituitaries in response to neuropeptide Y (NPY) treatment. Anterior hypothalamic (AH) and mediobasal hypothalamic (MBH) blocks of tissues and the adenohypophysis were bisected along the midline into two equal-sized fragments. Fragments were superfused with medium for 3 h, followed by 3 h of either NPY (80 nM) or medium alone. In a separate experiment, adenohypophyseal (AP) fragments were superfused in accordance with the same protocol (3 h medium – 3 h NPY or medium) except that exogenous GnRH (352 nM) was added for 30 min at the beginning of hour 3 and again at the beginning of hour 6. Immunoactive GnRH, β-EP, and LH levels were measured in superfusate samples (400 µl) collected at 10-min intervals. GnRH levels rose within 20–30 min of initiation of NPY treatment, and elevated GnRH release was sustained for the duration of NPY exposure of both AH and MBH fragments from ovarian intact (INT) rhesus (Macaca mulatta; n = 8; p < 0.05) or Japanese (Macaca fascicularis; n = 4; p < 0.01) macaques. NPY treatment had no effect on either AH or MBH fragments isolated from ovariectomized (OVX) rhesus macaques (n = 4 for AH, and n = 5 for MBH). In AP fragments isolated from INT rhesus macaques (n = 8), NPY stimulated LH release within 1 h of treatment (p < 0.05), whereas NPY had no effect on pituitaries from OVX animals (n = 4). Exogenous GnRH stimulated LH release within 20 min; however, the administration of NPY did not alter the responsiveness of Japanese macaque pituitaries to GnRH (p > 0.05; n = 7). NPY treatment had no effect on β-EP release from AH, MBH, and AP tissues of either INT or OVX rhesus macaques. These findings suggest that (1) the stimulatory action of NPY on GnRH release in macaque hypothalami and LH release in macaque anterior pituitaries requires functioning ovaries; (2) NPY does not enhance the sensitivity of macaque gonadotropes to GnRH stimulation, and (3) the mechanism of stimulatory NPY action may not involve the neuronal release of β-EP.