Responsiveness of cytosolic free calcium concentration in cultured rat pulmonary arterial smooth muscle cells: confocal microscopic measurement.
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 Ca2+ 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 Ca2+ concentration ([Ca2+]i) were examined. KCl, a depolarizing agent, and norepinephrine, an alpha-adrenergic agonist, equally increased [Ca2+]i. Angiotensin II, a receptor agonist, and caffeine, a Ca(2+)-induced Ca2+ releaser, elevated [Ca2+]i in the same manner but was more potent than KCl and norepinephrine. Br-A23187, a Ca2+ ionophore, most potently increased [Ca2+]i. The present results suggest that drug receptors on plasma membrane, Ca2+ 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 Ca2+ in vasoconstriction.
Li
Z
Z
Department of Pharmacology, China Medical College, Shenyang, China.
Zhang
Q
Q
Zhao
S
S
Wei
M
M
Shenghui
Z
Z
Cong
H
H
Ouda
H
H
Odajima
K
K
Takemura
H
H
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism*; D008168:Lung / Q000098:blood supply*; D008297:Male; D018613:Microscopy, Confocal; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011945:Receptors, Angiotensin / Q000819:agonists
D000316:Adrenergic alpha-Agonists; D011945:Receptors, Angiotensin; D000001:Calcimycin; D002110:Caffeine; D011189:Potassium Chloride; D002118:Calcium; D009638:Norepinephrine