Effects of Mitragynine on cAMP Formation Mediated by .DELTA.-Opiate Receptors in NG108-15 Cells

Autor: Shin-ichiro Sakai, Norio Aimi, Pavich Tongroach, Hiromitsu Takayama, Yukihisa Murakami, Suchitra Thongpraditchote, Michihisa Tohda, Hiroshi Watanabe, Kinzo Matsumoto
Rok vydání: 1997
Předmět:
Zdroj: Biological and Pharmaceutical Bulletin. 20:338-340
ISSN: 1347-5215
0918-6158
DOI: 10.1248/bpb.20.338
Popis: Mitragynine, a major constituent of the young leaves of Mitragyna speciosa KORTH., has been reported to exert antinociceptive activity in mice. To determine the mechanism the influence of mitragynine on cAMP content was measured in NG108-15 cells which possess delta opioid receptors and alpha 2B-adrenoceptors. Mitragynine inhibited the forskolin-stimulated cAMP content in a concentration dependent manner as well as morphine and noradrenaline. Mitragynine- and morphine-induced inhibition of cAMP content were blocked by naloxone. Although idazoxane inhibited noradrenaline-induced inhibition of the cAMP content, idazoxane had no effect on mitragynine-induced inhibition. These results suggest that mitragynine acts directly on opioid receptors, but not on alpha 2-adrenoceptors, to show antinociceptive activity.
Databáze: OpenAIRE