Responsiveness of cytosolic free calcium concentration in cultured rat pulmonary arterial smooth muscle cells: confocal microscopic measurement
Li, Z.; Zhang, Q.; Zhao, S.; Wei, M.; Shenghui, Z.; Cong, H.; Ouda, H.; Odajima, K.; Takemura, H.
Research Communications in Molecular Pathology and Pharmacology 97(1): 47-52
1997
ISSN/ISBN: 1078-0297 PMID: 9507567 Document Number: 483317
Rat pulmonary arterial smooth muscle cells were primarily cultured. alpha-actins in pulmonary arterial smooth muscle cells at day 7 of culture were observed by an immunofluorescence staining method using anti-alpha-actin antibody. Microfluorimetry of Ca-2+ signals in fluo-3-loaded single smooth cell at day 7 of culture was performed by a laser-scanned confocal imaging system. The effects of several kinds of Ca-2+-mobilizing drugs on cytoplasmic Ca-2+ concentration ((Ca-2+)-i) were examined. KCl, a depolarizing agent, and norepinephrine, an alpha-adrenergic agonist, equally increased (Ca-2+)-i. Angiotensin II, a receptor agonist, and caffeine, a Ca-2+-induced Ca-2+ releaser, elevated (Ca-2+)-i in the same manner but was more potent than KCl and norepinephrine. BrA23187, a Ca-2+ ionophore, most potently increased (Ca-2+)-i. The present results suggest that drug receptors on plasma membrane, Ca-2+ entry pathways and Ca-2+-releasing mechanisms act normally, and that our cultured pulmonary arterial smooth muscle cells may be a good model for the study on the essential role of Ca-2+ in vasoconstriction.