Serotonin increases Na(+)-dependent Ca2+ efflux from bovine adrenal chromaffin cells in culture.
The effect of serotonin (5-hydroxytryptamine, 5-HT) on Ca2+ mobilization in bovine adrenal chromaffin cells in culture was examined. 5-HT (10(-5) M) did not increase secretion of catecholamine, uptake of 45Ca2+ and levels of intracellular free Ca2+ ([Ca/+]i). However, 5-HT (10(-8)-10(-5) M) stimulated the efflux of 45Ca2+ from cultured bovine adrenal chromaffin cells in a concentration-dependent manner. Its stimulatory effect on 45Ca2+ efflux was inhibited by cyproheptadine (a 5-HT1A and 5-HT2 receptor antagonist) or mianserin (a 5-HT2 receptor antagonist). The increase in 5-HT-stimulated 45Ca2+ efflux was dependent on extracellular Na+ concentration, but not extracellular Ca2+ concentration. These results indicate that stimulation of the 5-HT receptors induces extracellular Na(+)-dependent Ca2+ efflux from bovine adrenal chromaffin cells in culture, probably by acceleration of Na+/Ca2+ exchange.
Minakuchi
K
K
Department of Pharmacy, School of Medicine, University of Tokushima, Japan.
Houchi
H
H
Yoshizumi
M
M
Ishimura
Y
Y
Morita
K
K
Takasugi
M
M
Oka
M
M
Tamaki
T
T
D000311:Adrenal Glands / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D019439:Chromaffin Cells / Q000378:metabolism*; D003533:Cyproheptadine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007425:Intracellular Membranes / Q000378:metabolism; D008803:Mianserin / Q000494:pharmacology; D009994:Osmolar Concentration; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D012964:Sodium / Q000502:physiology*
D012702:Serotonin Antagonists; D008803:Mianserin; D003533:Cyproheptadine; D012701:Serotonin; D012964:Sodium; D002118:Calcium