AL-Hader A A, Lei Z M, Rao C V
Laboratory of Molecular Reproductive Biology and Medicine, Department of Obstetrics and Gynecology, University of Louisville Health Sciences Center, Kentucky 40292, USA.
Biol Reprod. 1997 Feb;56(2):501-7. doi: 10.1095/biolreprod56.2.501.
Adult rat brains contain LH/hCG receptors, and these receptors are functional in neuroendocrine regulation and behaviors. Since glial cells are important for development, maturation, and functioning of the brain, we tested the hypothesis that these cells from neonatal rat brains may also contain functional LH/hCG receptors. Reverse-transcriptase polymerase chain reaction amplified an expected 256 base-pair LH/hCG receptor fragment from glial cells. This fragment can bind to LH/hCG receptor cDNA in Southern blotting. Northern blotting demonstrated that glial cells contain a major 2.6-kilobase (kb) and a minor 4.3-kb transcript of LH/hCG receptors. Western immunoblotting demonstrated that glial cells also contain an 80-kDa receptor protein and that its levels are significantly higher in secondary and tertiary glial cells than in primary glial cells. Immunocytochemistry confirmed that LH/hCG receptor immunostaining is present in glial cells. Since glial cells are quite active in synthesis of prostaglandins (PGs), we investigated the effect of highly purified hCG on PGD2 and PGE2 levels. The results showed that culturing secondary glial cells for three days with highly purified hCG resulted in a dose-dependent and hormone-specific increase in PGD2 and a decrease in PGE2 levels in the medium as compared to control levels. In summary, we conclude that cultured glial cells from neonatal rat brains contain functional LH/hCG receptors. Through regulation of PG synthesis, LH and hCG may influence glial cell functions that are important for neonatal brain development and function.
成年大鼠大脑中含有促黄体生成素/人绒毛膜促性腺激素（LH/hCG）受体，这些受体在神经内分泌调节和行为中发挥作用。由于神经胶质细胞对大脑的发育、成熟和功能很重要，我们检验了这样一个假设，即新生大鼠大脑中的这些细胞可能也含有功能性LH/hCG受体。逆转录聚合酶链反应从神经胶质细胞中扩增出了预期的256个碱基对的LH/hCG受体片段。该片段在Southern印迹中可与LH/hCG受体cDNA结合。Northern印迹显示神经胶质细胞含有一条主要的2.6千碱基（kb）和一条次要的4.3-kb的LH/hCG受体转录本。蛋白质免疫印迹表明神经胶质细胞还含有一种80-kDa的受体蛋白，且其在二级和三级神经胶质细胞中的水平显著高于原代神经胶质细胞。免疫细胞化学证实神经胶质细胞中存在LH/hCG受体免疫染色。由于神经胶质细胞在前列腺素（PGs）合成方面相当活跃，我们研究了高度纯化的hCG对PGD2和PGE2水平的影响。结果表明，与对照水平相比，用高度纯化的hCG培养二级神经胶质细胞三天导致培养基中PGD2呈剂量依赖性和激素特异性增加，而PGE2水平降低。总之，我们得出结论，新生大鼠大脑中培养的神经胶质细胞含有功能性LH/hCG受体。通过调节PG合成，LH和hCG可能会影响对新生大脑发育和功能很重要的神经胶质细胞功能。
