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Homologous Desensitization of Serotonin 5‐HT 2 Receptor‐Stimulated Intracellular Calcium Mobilization in C6BU‐1 Glioma Cells via a Mechanism Involving a Calmodulin Pathway
Author(s) -
Kagaya Ariyuki,
Mikuni Masahiko,
Muraoka Shinichiro,
Saitoh Kazuko,
Ogawa Tetsuo,
Shinno Hideto,
Yamawaki Shigeto,
Takahashi Kiyohisa
Publication year - 1993
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1993.tb03619.x
Subject(s) - homologous desensitization , desensitization (medicine) , serotonin , calmodulin , intracellular , receptor , calcium in biology , 5 ht receptor , endocrinology , medicine , antagonist , receptor antagonist , calcium , chemistry , biology , microbiology and biotechnology
Serotonin 5‐HT 2 receptor‐mediated intracellular Ca 2+ mobilization was investigated in rat glioma C6BU‐1 cells. The receptors became desensitized after previous exposure to 5‐HT in a time‐and concentration‐dependent manner. The desensitization of 5‐HT 2 receptor‐mediated intracellular signaling appeared to be homologous because previous exposure to 5‐HT did not alter the response to other transmitters such as thrombin or isoproterenol and because previous exposure to thrombin or isoproterenol did not diminish the response to 5‐HT. The desensitization induced by pretreatment with 5‐HT was potently prevented by the naphthalenesulfonamide derivative W‐7, a calmodulin antagonist, when it was cosupplied with 5‐HT. Furthermore, the preventive effect of W‐7 was greater than that of W‐5, a weak analogue of W‐7, and than that of H‐7, a nonselective inhibitor of protein kinases. These results suggest that 5‐HT 2 receptor‐mediated Ca 2+ mobilization can be desensitized homologously after prolonged exposure to 5‐HT in a calmodulin‐dependent manner in rat glioma C6BU‐1 cells.