The calcium-related basis of action of adenosine in rabbit aortic smooth muscle

• Published in: General pharmacology Vol. 21; no. 5; p. 671
• Main Authors: Zawadzki, J V, Weiss, G B
• Format: Journal Article
• Language: English
• Published: England 1990
• Subjects: Adenosine - pharmacology; Animals; Aorta, Thoracic - drug effects; Calcium - physiology; Calcium Radioisotopes; Egtazic Acid - pharmacology; In Vitro Techniques; Lanthanum - pharmacology; Male; Muscle Contraction - drug effects; Muscle, Smooth, Vascular - drug effects; Norepinephrine - pharmacology; Potassium Chloride - pharmacology; Rabbits
• ISSN: 0306-3623
• DOI: 10.1016/0306-3623(90)91015-J

1. In rabbit aortic smooth muscle, adenosine inhibited the increase induced by norepinephrine (NE) in 45Ca uptake in the presence of KCl (under low affinity Ca2+ uptake conditions) and the NE-induced decrease in 45Ca uptake (under high affinity Ca2+ uptake conditions). Basal 45Ca uptake and KCl-stimulated 45Ca uptake were not altered by adenosine. 2. Adenosine blocked the NE-induced contraction (in high K+) and inhibited both the tonic and phasic components of the NE-induced contraction. 3. Thus, adenosine selectively inhibits release of the intracellular Ca2+ store important for the phasic response to NE and that Ca2+ uptake component important for the NE-induced tonic response.