Protective effect of colectomy in frog virus 3 hepatitis of rats: possible role of endotoxin.

Four to six days after colectomy, rats resisted a challenge of frog virus 3 that in sham-operated animals led to lethal hepatitis. Furthermore, the beneficial effect of colectomy was lost after intravenous administration of a dose of bacterial endotoxin as small as 0.01 100% lethal dose. The protection was related to neither a different distribution of the virus in body organs nor a stimulation of the reticuloendothelial system. The virus-induced early events--destruction of liver sinusoidal cells with leakage of cathepsin D into serum and inhibition of liver macromolecular synthesis--evolved similarly in both groups of rats. After an identical consumption of complement at the beginning of infection, a renewal in complement activity in the protected rats contrasted with an increasing deficiency in the control animals. The protective role of colectomy seems to be related to the suppression of the main source of bacterial endotoxin.