Effects of 3-morpholinosydnonimine-N-ethylcarbamide on hypoxia-induced mechanical and electric responses of isolated pig coronary artery.
OBJECTIVE
To study effects of 3-morpholinosydnonimine-N -ethylcarbamide (SIN-1) on hypoxia-induced mechanical and electric activities of the isolated pig coronary artery.


METHODS
Mechanical tension and membrane potential were measured simultaneously.


RESULTS
Hypoxia initially caused a transient vascular smooth muscle cell membrane hyperpolarization followed by a membrane depolarization in isolated pig coronary artery. Subsequent addition of SIN-1 100 mumol . L-1 or verapamil (Ver) 10 mumol . L-1 led to membrane repolarization and relaxation of the vascular smooth muscle. Nitro-L-arginine (NLA) 0.2 mmol . L-1 and KCI 40 mmol . L-1 also induced membrane depolarization and vasoconstriction, which were similarly suppressed by SIN-1 or Ver.


CONCLUSIONS
Hypoxic contractile response in isolated pig coronary artery is mediated by an increased Ca2+ influx via suppression of nitric oxide release.
Yang
X P
XP
Department of Pharmacology, Hebei Medical College, Shijiazhuang, China.
Wang
F X
FX
Ren
D C
DC
Lu
S C
SC
Fu
S X
SX
Li
Y S
YS
D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D000860:Hypoxia / Q000503:physiopathology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D008981:Molsidomine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D013552:Swine; D014665:Vasodilator Agents / Q000494:pharmacology*
D014665:Vasodilator Agents; C002385:linsidomine; D008981:Molsidomine