一氧化氮对培养的大鼠垂体黄体生成素和卵巢雌二醇释放的影响

目的　探讨一氧化氮对垂体前叶黄体生成素 (LH)及卵巢雌二醇 (E2 )释放的调节作用。方法　在大鼠垂体组织培养液及卵巢组织培养液中分别加入不同浓度的一氧化氮生成抑制剂N 硝基 L 精氨酸 (NNLA)或N 硝基 L精氨酸甲酯 (NAME)和一氧化氮供体硝普钠 (SNP) ,孵育 6 0min ,收集培养液 ,用放射免疫法测定其中LH、E2 含量。结果　NNLA增加垂体组织培养液中的LH含量 ,NAME可增加卵巢组织培养液中的E2 的含量 ,而SNP则使LH及E2 含量减少 ,这些作用具有剂量依赖性。当NNLA或NAME的浓度为 5× 10 -3 mol·L-1时 ,LH及E2 含量分别增加至基础水平的 5 .5倍及 2 .0倍 ,而当SNP浓度为 5× 10 -3 mol·L-1时 ,LH及E2 含量则分别减至基础水平的 5 0 %及 36 %。结论　一氧化氮抑制垂体前叶LH及卵巢E2 的释放 ,可能在垂体及卵巢的功能调节中起重要作用。

Influence of nitric oxide on the release of luteining hormone and estradiol from cultured pituitary and ovary tissues of rats

Objective To study the regulation of nitric oxide on the release of luteining hormone (LH) from the pipuitary and estradiol (E 2) from the ovary. Methods Nitric oxide synthase inhibitors, N G-nitro-L-arginine(NNLA) and N G-nitro-L-arginine methyl ester (NAME), and nitric oxide donor, sodium nitroprusside (SNP) at various concentrations were, respectively, added into the culture solutions, in which the rat pipuitary and ovary tissues were cultured. After 60 mins, culture solutions were collected, and the LH and E 2 contents were determined by radioimmunoassay.Results NNLA and NAME increased, and SNP decreased LH and E 2 contents in the culture solutions, respectively, in a dose-dependent manner. LH and E 2 contents were, respectively, increased by 5.5 and 2.0 times, and decreased by 50% and 36% over the base level at concentration of 5×10 -3 mol·L -1 of the agents used. Conclusion Nitric oxide inhibits LH release from the anterior pipuitary and E 2 from the ovary, and may play an important role in regulating pipuitary and ovary functions.