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F Karmeli

Publications and source records attributed to F Karmeli.

98 records · Page 6Linked to original sources

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

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.

Adenosine Triphosphatases↗

Functional and morphological alterations following isolated rat stomach irradiation. A model for estimation of radiation injury.

Exposure of the stomach to tumoricidal doses of radiation is associated with functional and morphological changes. The experimental data have been mainly obtained from studies of whole body irradiation of the stomach. We investigated the separate effect of irradiation on the surgically exposed stomach with doses of between 3 and 30 Gy. A dose-dependent decrease in free and total acidity was observed with relatively low doses (5-9 Gy). Serum pepsinogen and serum gastrin levels increased following irradiation with doses ranging from 5 to 15 Gy. Two phases of increased regenerative activity were documented (between the 1st and 3rd weeks and between the 4th and 8th weeks). No radioprotective effect was observed when sucralfate or misoprostol were utilized. Further investigations are mandatory in order to find an effective radioprotector for the irradiated stomach.

Animals↗