Experimental production of pigment gallstones in rats -with special reference to the effects of diet.

We attempted to produce experimental gallstones in rats by inducing incomplete obstruction of the terminal common bile duct under conditions of a low protein diet and rat chow, and we then studied the influence of each diet on the gallstone formation. The incidence of dilatation of the common bile duct in the low protein group was significantly higher than in the rat chow group. Two of 13 rats with a dilated common bile duct after a low protein diet had pigment gallstones. Histological examination of the common bile ducts showed that the gallstones included an extensive cholangitis. It is thus concluded that bile stasis and infection are important factors in the formation of pigment gallstone, and a low protein diet plays a considerable role as a predisposing factor.