[Effect of emodin on motility signal transduction in colonic smooth muscle cells in rats with multiple organ dysfunction syndrome].

ABSTRACT

OBJECTIVE: To observe the effect of emodin on motility signal transduction and calcium ion in colonic smooth muscle cells (SMC) in rats with bacterial peritonitis caused multiple organ dysfunction syndrome (MODS). METHODS: Observation was conducted in colon of MODS model rats on (1) effects of emodin on the contraction of muscular strip and cells of colonic smooth muscle, and influences of specific myoglobulin light chain kinase inhibitor (ML-7) and selective proteinkinase C inhibitor (Calphostin C) on these effects; and (2) effect of emodin on calcium ion in SMC. RESULTS: Emodin could directly contract the muscular strip and cells of smooth muscle; ML-7 and Calphostine could inhibit these contractile action to some extent. Under MODS condition, emodin could still increase the intracellular calcium ion concentration; this effect could be inhibited by heparin (inosamine triphosphate receptor inhibitor IP3 and ryanodine receptor inhibitor in MODS model but the calcium chelator EGTA and nifedipine (the specific cell membrane voltage dependent calcium channel blocker) showed no influence on it. CONCLUSION: Emodin could directly contract the colonic smooth muscle in MODS model rats, which is mediated by raise the signal path MLCK of calcium ion and the PKCa path for increase calcium sensibility. The mechanism of increasing calcium ion is mainly through IP3 and RyR the two calcium ion channel receptor in the sarcoplasm.