Inhibition of oxidative phosphorylation, vascular tone, and [Ca2+]i in the perfused rat tail artery.
We investigated the possibility that the inhibition of oxidative phosphorylation in vascular smooth muscle attenuates norepinephrine- or KCl-evoked vasoconstriction with no change in mobilization of intracellular calcium concentration ([Ca2+]i). Experiments were performed in perfused segments of the rat tail artery loaded with the intracellular calcium dye fura 2, in the absence and presence of dinitrophenol or sodium cyanide; inhibition of oxidative phosphorylation was evaluated from the fall in intracellular ATP levels. The metabolic inhibitors reduced vasoconstriction with no change in [Ca2+]i handling, suggesting that 1) inhibition of oxidative phosphorylation attenuates vasoconstriction via a mechanism downstream of [Ca2+]i, and 2) [Ca2+]i homeostasis (both increases and decreases in [Ca2+]i) can be maintained in the presence of inhibitors of oxidative phosphorylation.
Tran
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NN
Laboratoire de Pharmacologie Cardio-vasculaire, Faculté de Pharmacie, Université Henri Poincaré-Nancy 1, France.
Robert
A
A
Atkinson
J
J
Capdeville-Atkinson
C
C
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000378:metabolism*; D004140:Dinitrophenols / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009129:Muscle Tonus / Q000187:drug effects / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology*; D010085:Oxidative Phosphorylation / Q000187:drug effects; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012966:Sodium Cyanide / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
D004140:Dinitrophenols; D011189:Potassium Chloride; D000255:Adenosine Triphosphate; D012966:Sodium Cyanide; D002118:Calcium; D009638:Norepinephrine