Inhibitory Action of the General Anesthetic Ketamine on Intracellular Calcium Transients and Smooth Muscle Contractions of the Mouse Small Intestine

Abstract

The mechanisms of the negative consequences of general anaesthetics action on the nervous system have been studied in detail, but regarding smooth muscle function, such issues have not yet been sufficiently addressed. In this study, we investigated the effect of the general intravenous anaesthetic ketamine on the level of intracellular calcium in isolated ileum myocytes and the contractile activity of smooth muscle strips of the mouse small intestine. The concentration of intracellular calcium in cells was measured using the Ca2+-sensitive fluorescent dye Fura-2, and tensiometry was used to record the contractile activity of smooth muscles. It was shown that ketamine at a concentration of 100 µM significantly, by 40%, suppressed carbachol-induced contractile reactions of the ileum. The inhibitory effect correlated with the suppression of the intracellular calcium responses to carbachol in isolated smooth muscle cells after the addition of ketamine to the extracellular solution, which was by 65% on average. These results contribute to our better understanding of the possible membrane and intracellular mechanisms of the development of post-surgical intestinal motility disorders.