Experimental Formation of Gallstones in the Squirrel Monkey

SummarySquirrel monkeys fed a semi-purified diet to induce atherosclerosis showed a high incidence of gallstones, which began to appear 3 months after the start of the atherogenic diet. The incidence in animals maintained on this diet for over 9 months was 83%. The gallstones consisted essentially of pure cholesterol and increased in size, number, and total mass of stones during the period of feeding. The cholesterol: phospholipid ratio in bile was highest in the group and in the individuals with stones. Monkeys fed a natural diet had very low ratios and were free of gallstones.