Effects of ouabain on contractile response to norepinephrine in isolated rat aorta.
1. Inhibition of sodium(Na+), potassium(K+)-ATPase activity was dependent on the concentration of ouabain and inverse to the concentration of potassium ([K+]) in the reaction mixture. 2. Contractility of isolated rat aorta preparation in response to norepinephrine was augmented by ouabain and low [K+]. 3. Results suggest that inhibition of Na+,K(+)-ATPase activity will be correlated with augmentation of vascular contractility maybe through activation of Na(+)-calcium exchange system.
Moromizato
H
H
Department of Pharmacology, School of Medicine, University of the Ryukyus, Okinawa, Japan.
Miyagi
H
H
Nakayama
M
M
Higuchi
M
M
Sakanashi
M
M
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000201:enzymology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000201:enzymology; D009638:Norepinephrine / Q000494:pharmacology*; D010042:Ouabain / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors
D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D009638:Norepinephrine