Characterization of homologous 5-hydroxytryptamine sub(4) receptor desensitization in colliculi neurons
Exposure of mouse colliculi neurons to selective 5-hydroxytryptamine (5-HT) sub(4) agonists was accompanied by a rapid desensitization of the receptor-stimulated adenylyl cyclase response. Half-maximal desensitization occurred after 2 min. Only exposure of neurons to selective 5-HT sub(4) agonists l...
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Published in | Molecular pharmacology Vol. 42; no. 5; pp. 808 - 816 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
01.01.1992
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Subjects | |
Online Access | Get full text |
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Summary: | Exposure of mouse colliculi neurons to selective 5-hydroxytryptamine (5-HT) sub(4) agonists was accompanied by a rapid desensitization of the receptor-stimulated adenylyl cyclase response. Half-maximal desensitization occurred after 2 min. Only exposure of neurons to selective 5-HT sub(4) agonists led to a potent desensitization of the 5-HT sub(4)-mediated response. Neurons exposed to other agents, like isoproterenol, vasoactive intestinal peptide, or forskolin, that increase cAMP levels did not undergo any desensitization of 5-HT sub(4) receptors. Activation of protein kinase A with either 8-bromo-cAMP or dibutyryl-cAMP or application of inhibitors of protein kinase A-dependent phosphorylation did not change the rate of 5-HT sub(4)-induced desensitization. No shift to lower potency of 5-HT sub(4) agonists in the concentration-response curve was observed. These results suggest that 5-HT sub(4) receptor agonists induced homologous but not cAMP-mediated heterologous desensitization. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 content type line 23 ObjectType-Feature-1 |
ISSN: | 0026-895X |