Mechanism of histamine-induced calcium efflux from cultured bovine adrenal chromaffin cells: possible involvement of an Na+/Ca2+ exchange mechanism.
The effect of stimulation of the histamine receptor on Ca2+ mobilization in cultured bovine adrenal chromaffin cells was examined. Histamine (10(-5) M) increased the intracellular free Ca2+ ([Ca2+]i) to a peak in the presence or absence of extracellular Ca2+, followed by decrease with time. Histamine (10(-8)-10(-5) M) also stimulated 45Ca2+ efflux from cultured bovine adrenal chromaffin cells in a concentration dependent manner. Its stimulatory effect on 45Ca2+ efflux was inhibited by the specific histamine H1 receptor antagonist mepyramine. The increase in histamine-stimulated 45Ca2+ efflux was inhibited by deprivation of extracellular Na+ and by the Na+/Ca2+ exchange inhibitor amiloride. In addition, histamine stimulated 22Na+ influx into the cells, and this action was inhibited by amiloride. These results suggest that stimulation of the histamine H1 receptor regulates Na+/Ca2+ exchange in cultured bovine adrenal chromaffin cells.
Houchi
H
H
Department of Pharmacology, Tokushima University School of Medicine, Japan.
Kitamura
K
K
Minakuchi
K
K
Ishimura
Y
Y
Okuno
M
M
Ohuchi
T
T
Oka
M
M
D000313:Adrenal Medulla / Q000187:drug effects* / Q000378:metabolism; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology*; D007424:Intracellular Fluid / Q000378:metabolism; D011738:Pyrilamine / Q000494:pharmacology; D011969:Receptors, Histamine H1 / Q000502:physiology; D015398:Signal Transduction; D012964:Sodium / Q000378:metabolism*; D019831:Sodium-Calcium Exchanger
D002352:Carrier Proteins; D011969:Receptors, Histamine H1; D019831:Sodium-Calcium Exchanger; D000584:Amiloride; D006632:Histamine; D012964:Sodium; D011738:Pyrilamine; D002118:Calcium