[Heterogeneities in intracellular Ca2+ pools among different arterial smooth muscle cells and its possible role in vascular reactivities in rat].
The differences in intracellular Ca2+ pool capacities, the mutual relations between different agonist-sensitive Ca2+ pools (ASCaP) and between ASCaP and caffeine-sensitive Ca2+ pool (CSCaP), and the possible role of Ca2+ pool capacity in vascular reactivities in different isolated artery rings of rat in Ca(2+)-free media were studied by using the tension of vascular smooth muscle as an indicator of Ca2+ release. The study showed the following findings: (1) the Ca2+ pools were significantly different in capacities in different arteries (renal artery > mesenteric artery > caudal artery > aorta > pulmonary artery); (2) different ASCaPs were partially "overlapped", i.e., when one ASCaP was depleted, other kind of agonist could still induce a small but significant Ca2+ release; (3) the CSCaP was present in all the arteries tested, but it was not the same pool with the ASCaP; (4) there were no high-K+ depolarization-induced Ca2+ release in all the arteries tested and (5) there was a positive correlation between the maximal contraction (Emax expressed as mg force/mg muscle wet weight) and the Ca2+ pool capacities, suggesting that there is a role of Ca2+ pool capacities in the vascular contractilities.
Cao
J
J
Institute of Basic Medical Sciences, CAMS, Beijing.
Chen
M
M
Wang
Q
Q
D000818:Animals; D001011:Aorta / Q000502:physiology; D019540:Area Under Curve; D001127:Arginine Vasopressin / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels; D008297:Male; D008638:Mesenteric Arteries / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D011651:Pulmonary Artery / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012077:Renal Artery / Q000502:physiology
D015220:Calcium Channels; D001127:Arginine Vasopressin; D002110:Caffeine; D002118:Calcium