Agonist-induced calcium transients in cultured smooth muscle cells: measurements with fura-2 loaded monolayers.
Elevation of cytosolic Ca2+ in response to depolarization and various receptor agonists was measured in several types of cultured smooth muscle cells (DDT1, A10, rabbit aorta) loaded with the either quin-2 or fura-2, and assayed either in suspension or in monolayer cultures attached to plastic cover slips. Agonists (norepinephrine, vasopressin) induced both the release of intracellular Ca2+ and the influx of extracellular Ca2+. Agonist-induced Ca2+ influx was not blocked by dihydropyridines, and depolarization did not induce Ca2+ influx. However, in fura-2 loaded monolayers of PC12 cells, depolarization did induce dihydropyridine-sensitive Ca2+ influx. Thus cultured smooth muscle cells appear to express receptor-operated Ca2+ channels, but not functional voltage-operated Ca2+ channels.
D000634:Aminoquinolines / Q000378:metabolism; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D001572:Benzofurans / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002217:Carbachol / Q000494:pharmacology; D002460:Cell Line; D006224:Cricetinae; D004987:Ethers / Q000494:pharmacology; D016257:Fura-2; D015759:Ionomycin; D008297:Male; D008647:Mesocricetus; D009130:Muscle, Smooth / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D009543:Nifedipine / Q000031:analogs & derivatives / Q000494:pharmacology; D009568:Nitrendipine; D009638:Norepinephrine / Q000494:pharmacology; D011817:Rabbits; D012701:Serotonin / Q000494:pharmacology; D014667:Vasopressins / Q000494:pharmacology
D000634:Aminoquinolines; D001572:Benzofurans; D004987:Ethers; D014667:Vasopressins; D000804:Angiotensin II; D001127:Arginine Vasopressin; D012701:Serotonin; D015759:Ionomycin; D002217:Carbachol; D009568:Nitrendipine; D009543:Nifedipine; C035739:Quin2; D002118:Calcium; D016257:Fura-2; D009638:Norepinephrine