Effect of colchicine and vinblastine on rat intestinal water transport and Na-K-ATPase activity.

Publisher Website
Google Scholar
Abstract
The hypothesis that colchicine and vinblastine, which are commonly used for therapeutic purposes and known to cause diarrhoea, decrease intestinal water transport by inhibition of Na-K-ATPase activity was tested in rats. Net fluid transport by jejunal segments was measured four hours after intraperitoneal injection of either 0.15 M NaCl (0.5 ml/100 g), colchicine (0.5 mg/100 g b.w.), or vinblastine (1.0 mg/100 g b.w.). Colchicine and vinblastine decreased net fluid transport: 3.0 +/- 0.9 (SE) and 4.6 +/- 0.4 (SE) respectively, as compared to that transported by segments from rats injected with 0.15 M NaCl, 8.6 +/- 0.7 (SE) g fluid/hour/g. Methylprednisolone (3.0 mg/100 g b.w.) abolished the inhibitory effect of cholchicine and vinblastine on fluid transport. Colchicine and vinblastine were found to decrease significantly mucosal Na-K-ATPase activity, 18.2 +/- 4.9 (SE); 25.2 +/- 2.4 (SE) respectively, as compared to that measured in rats injected with saline 40.6 +/- 3.4 (SE) mumol/mg protein/hour. Pretreatment with methylprednisolone prevented the decrease in enzyme activity observed in rats injected with colchicine and vinblastine. The degree of inhibition in intestinal Na-K-ATPase activity was similar to that observed in fluid transport following colchicine and vinblastine. It is thus suggested that colchicine-induced inhibition of water transport is caused by inhibition of Na-K-ATPase activity, an effect which can be prevented by pretreatment with methyl-prednisolone.