Cellular redox homeostasis mediates contractility of isolated ileum of male Wistar rats

Abstract

Redox-mediated mechanisms play an important role in regulating smooth muscle contractility and depend on subtle redox homeostasis maintaining. Redox homeostasis in cells is obtained by the activity of antioxidant enzymes. Among them, glutathione reductase constantly reduces oxidized glutathione, providing a favorable cellular redox milieu. The aim of this study was to examine whether, to what extent and in what way changes in smooth muscle contractility occurred in conditions when glutathione reductase activity was changed. The experiments were performed on isolated ileum of male Wistar rats, electrically stimulated and treated with cumulative doses of carmustine, a glutathione reductase inhibitor. The activity of antioxidant enzymes(catalase, glutathione reductase and glutathione peroxidase, as well as the amount of total SH groups and glutathione) was determined in treated ileum. The addition of carmustine inhibited glutathione reductase activity and decreased amplitude and frequency of electrically stimulated ileum. The results showed that glutathione reductase activity and maintenance of highly reductive cellular environment were essential to contractility processes.