[The role of extracellular calcium in the vasoconstriction evoked by endothelin-1].
Some mechanisms responsible for extracellular Ca++ entry into rat aortic smooth muscle cells were studied in response to endothelin-1 (ET-1). Isometric tension of de-endothelialized aortic strips was recorded. It was shown that the calcium-free medium or nifedipine blockade of calcium entry diminished responses to ET-1 to 20-30% of the control levels. Depolarization of the specimens with hyperpotassium solution also reduced constriction almost by 50%. When sodium ions were replaced by NMDG in the medium, a response to ET-1 showed a 50% reduction. The findings suggest that the potential-dependent calcium channels of the L-type are involved in cellular calcium entry, the opening of the channels depending upon the entry of Na+.
Zagulova
D V
DV
Pinelis
V G
VG
Markov
Kh M
KhM
Storozhevykh
T P
TP
Medvedev
M A
MA
Baskakov
M R
MR
Chabrier
E P
EP
Braque
P
P
D000818:Animals; D002118:Calcium / Q000494:pharmacology* / Q000502:physiology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D016232:Endothelins / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000502:physiology; D066298:In Vitro Techniques; D008536:Meglumine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009543:Nifedipine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects* / Q000502:physiology
D015220:Calcium Channels; D016232:Endothelins; D010656:Phenylephrine; D008536:Meglumine; D009543:Nifedipine; D002118:Calcium
Rol' vnekletochnogo kal'tsiia v vazokonstriktsii, vyzvannoĭ éndotelinom-1.