High responsiveness of cytosolic free calcium concentration to angiotensin II in cultured pulmonary arterial myocytes from pulmonary hypertensive rats.
Pulmonary arterial myocytes were cultured from normotensive and pulmonary hypertensive rats. Microfluorimetry of Ca2+ signals in fluo-3-loaded single myocytes at day 7 of culture was performed by a laser-scanned confocal imaging system. The resting level of cytoplasmic Ca2+ concentration ([Ca2+]i) in vascular myocytes obtained from hypertensive rats was higher than that in cultured myocytes obtained from normotensive rats. Angiotensin II elevated [Ca2+]i in the vascular myocytes cultured from both normotensive and hypertensive rats. However, a rise of [Ca2+]i induced by angiotensin II in the vascular myocytes obtained from pulmonary hypertensive rats was higher than that obtained from normotensive rats. On the other hand, the response of [Ca2+]i to A23187 did not differ between the vascular myocytes cultured from normotensive and hypertensive rats. The present results suggest that the resting and angiotensin II-responsive levels of [Ca2+]i in pulmonary arterial myocytes cultured from pulmonary hypertensive rats are higher than those cultured from normotensive rats.
Li
Z
Z
Department of Pharmacology, China Medical College, Shenyang.
Zhang
Q
Q
Zhao
S
S
Wei
M
M
Cong
H
H
Ouda
H
H
Odajima
K
K
Takemura
H
H
D000804:Angiotensin II / Q000494:pharmacology*; D000814:Aniline Compounds; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000032:analysis*; D002478:Cells, Cultured / Q000187:drug effects; D003600:Cytosol / Q000378:metabolism; D005456:Fluorescent Dyes; D006976:Hypertension, Pulmonary / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D011651:Pulmonary Artery / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014966:Xanthenes
D000814:Aniline Compounds; D005456:Fluorescent Dyes; D014662:Vasoconstrictor Agents; D014966:Xanthenes; D000804:Angiotensin II; C059715:Fluo-3; D000001:Calcimycin; D002118:Calcium