The inhibitory action of acetaldehyde on the tonic component of the potassium-induced contracture in the guinea-pig taenia caeci
Momose, Y.; Takeda, R.
Archives Internationales de Pharmacodynamie et de Therapie 255(1): 27-38
1982
ISSN/ISBN: 0003-9780 PMID: 7073397 Document Number: 184938
The effect of acetaldehyde on the contractile responses induced by K+-rich solution was studied in the guinea pig tenia caeci. Acetaldehyde at a concentration from 1-50 mM reduced the tonic contraction induced by a high K+ solution containing a normal CaCl2 concentration without affecting the phasic one. The phasic contraction was depressed only slightly at a very high concentration of acetaldehyde (100 mM). The tonic component increased with increasing external Ca concentration, and the reduction of this tonic contraction by acetaldehyde was greater at high Ca concentrations. In Ca-free, K-rich solution, carbachol induced a transient contraction. This carbachol-induced contraction in the absence of external Ca was markedly depressed at the 2nd application of carbachol, but it reappeared after exposure to Ca-containing solution. In this condition acetaldehyde did not affect these carbachol-responses, while it decreased a slow tension rise during Ca exposure. Evidently acetaldehyde inhibits external Ca entry without having an appreciable effect on Ca release and the filling of the internal stores with Ca.