Colchicine effects on the mouse liver.

With histochemical methods an instantaneous and marked inhibitory effect of a single dose of colchicine on the activity of succinic-, lactic-, glucose-6-phosphate-, NADH- and NADPH-dehydrogenase in the mouse liver was observed. This effect was essentially the same as that previously described in the intestinal mucosa and not dependent on or a consequence of the inhibitory effect of colchicine on cell division. The enzymatic inhibitory effect of colchicine was qualitatively similar regardless of the dose of the drug given, although a single large dose (1.5 mg/kg body weight) produced alterations and depression of dehydrogenase activity more marked and not so rapidly repaired as those appearing after a small dose of colchicine (0.24 mg/kg body weight). Following repeated doses of colchicine the degree of histochemically demonstrable depression of dehydrogenase activity was not obviously different from that found after a single dose. After large repeated doses morphological alterations and prolonged depression of dehydrogenase activity of liver cells were found and many of the animals died. After repeated administration of the small dose (0.24 mg/kg body weight) no morphological alterations were found and the activity of dehydrogenases was normalized, although the injection of colchicine was continued.