文章基本信息

标题：Regulation of the pro-opiomelanocortin mRNA levels in rat pituitary by dopaminergic compounds
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作者：C L Chen ; F T Dionne ; J L Roberts 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1983
卷号：80
期号：8
页码：2211-2215
DOI：10.1073/pnas.80.8.2211
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Dopamine-containing neurons directly innervate the intermediate lobe of the pituitary and dopaminergic compounds exert inhibitory effects on the secretion and the content of alpha-melanocyte-stimulating hormone and beta-endorphin in this tissue. In this study, we have investigated the effects of dopamine receptor agonists and antagonists on the level of pro-opiomelanocortin (POMC) mRNA in rat pituitary. RNAs isolated from neurointermediate pituitary (NIP) or anterior pituitary were spotted on nitrocellulose filters and the levels of POMC mRNA were quantified by hybridization to a POMC-specific complementary DNA probe coupled with autoradiography and densitometry. Administration of a dopamine receptor antagonist, haloperidol (2 mg/kg per day), to adult female rats resulted in a 3- to 5-fold increase in POMC mRNA level in the NIP. Treatment with the dopamine agonist 2-Br-alpha-ergocryptine (1 mg/kg per day) decreased significantly the content of POMC mRNA in the NIP. These drugs had no apparent effect on the POMC mRNA levels in the anterior pituitary. The effect of haloperidol and ergocryptine on POMC mRNA in the NIP is time- and dose-dependent. The elevation of POMC mRNA content in the NIP by haloperidol can be observed as early as 6 hr after treatment. These effects of dopaminergic compounds can also be demonstrated in adult male and ovariectomized female rats. The beta-endorphin content of the NIP, as measured by radioimmunoassay, and the de novo synthesis of POMC, as determined by radioactive amino acid labeling and two-dimensional gel electrophoresis analysis, also show negative regulation by dopaminergic compounds.