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:1977
卷号:74
期号:10
页码:4628-4632
DOI:10.1073/pnas.74.10.4628
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Hypophysectomized rats are supersensitive to the hypothermic effects of morphine and beta-endorphin injected intraventricularly as early as 1 week after surgery. At 2 weeks after surgery, there is a significant increase in the antinociceptive potency for these opiates. The route of opiate injection must be considered in interpretations of these results. The enhanced opiate potency following subcutaneous morphine injection in hypophysectomized rats may be partially explained by adrenal dysfunction, as demonstrated by a similar sensitization to subcutaneous morphine following adrenalectomy. By contrast, no enhancement of opiate potency was observed upon direct intraventricular injection of morphine or beta-endorphin in adrenalectomized rats. Furthermore, the potency of intravenous beta-endorphin is profoundly enhanced in adrenalectomized mice; five out of nine animals died when injected with a dose of the peptide that produced only mild analgesia in sham controls. The complete reversal of this intravenous beta-endorphin supersensitivity by dexamethasone implies a possible physiological interplay between the peptide and adrenal function.