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：1991
卷号：88
期号：19
页码：8671-8675
DOI：10.1073/pnas.88.19.8671
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：[Leu]- and [Met]enkephalin from thoracic ganglia of the shore crab Carcinus maenas have been purified to homogeneity by a reversed-phase HPLC procedure. Automated gas-phase sequencing revealed a primary structure identical with that of enkephalins from vertebrates. The immunoreactive material in different parts of the nervous system of C. maenas was measured by RIA. Isolated crustacean [Leu]enkephalin shows physiological properties identical to synthetic [Leu]enkephalin in our bioassay. The enkephalinergic effect has been monitored by two bioassays: (i) inhibition of release of crustacean hyperglycemic hormone from isolated eyestalks of C. maenas, and (ii) decreased effect on blood glucose level in the fiddler crab Uca pugilator. The decrease in blood sugar level induced by [Leu]enkephalin was antagonized by naloxone, indicating a receptor-mediated process. In sequence analysis, the thoracic ganglion yielded 3 pmol of [Leu]enkephalin and approximately 1 pmol of [Met]enkephalin. The presence of enkephalins in crustaceans shows an earlier phylogenetic origin of opioids than presumed.
