[Bile acid pool in the formation of pigment stone: an experimental study].

A method with isotopic 3H-CDCA was established to determine bile acid pool. Sixty male guinea pigs were divided randomly into two groups; 20 guinea pigs fed with standard chow served as control, and 40 with 10% low protein lithogenic chow were subdivided into 4 groups executed on 10,20,30 and 40 days (In the last subgroup, vitamin C was added to the chow), respectively. The bile acid pool of lithogenic animals decreased on the 10th days and significantly decreased on the 20th, 30th, 40th day (P < 0.01) when compared with controls in the same periods. The incidence of pigment gallstone was 90% on the 20th day, 100% on the 30th day, 40% on the 40th day in lithogenic animals. The pool size decreased slightly on the 40th day in lithogenic animals which were fed with supplement of Vitamin C. A significant positive correlation was noted between gallbladder volume and bile acid pool size (r = 0.842) in the 30th day lithogenic animals. We postulate that the decreased bile acid pool size occurs before the development of pigment gallstone and it may be an important factor in promoting the formation of gallstone.