Blockade or reversal of the contraction induced by calcium and adrenaline in depolarized arterial smooth muscle

Open Access
Publisher Website
Google Scholar
Abstract
1 Mesenteric arteries immersed in a depolarizing solution contract in the presence of calcium. These contractions are proportional to the calcium concentration and are reversible. 2 Mesenteric arteries immersed in a calcium-free depolarizing solution contract in the presence of adrenaline. Under the experimental conditions reported here, this response develops only about one-third of the contractile tension developed in polarizing solution (modified Krebs bicarbonate). 3 Cinnarizine and ohlorpromazine inhibit the contractile response to calcium and induce relaxation of depolarized muscle previously contracted by calcium; cinnarizine was 4 times more potent than chlorpromazine in such activity. 4 Chlorpromazine inhibits the response to adrenaline in both polarizing and calcium-free depolarizing solutions, whereas cinnarizine inhibits the response in polarizing solution but not that in calcium-free depolarizing solution. 5 The significance of these results is discussed.

This publication has 21 references indexed in Scilit: