In the present study, we examined the effect of the following factors on a hamster model of
cholesterol cholelithiasis: (i) the source of the golden Syrian hamsters (Sasco, Omaha, NE or Charles River, Wilmington, MA), (ii) the sex of the experimental animals and (iii) their age (4 wk vs. 8 wk of age). All hamsters were fed a semipurified diet which contained
cholesterol (0.3%) and
palmitic acid (1.2%). No
cholesterol gallstones formed in any of the female hamsters regardless of age or source. The 4-week-old male hamsters from Sasco had the greatest incidence of
gallstones (93%). The 8-week-old male hamsters tended to have a lower incidence of
cholesterol gallstones than the younger ones, regardless of the commercial supplier (67 vs. 93% for Sasco and 27 vs. 40% for Charles River). Female hamsters had higher liver and serum
cholesterol levels than the male hamsters; Charles River hamsters had lower serum
cholesterol concentrations than the Sasco animals. Total biliary
lipid concentrations were highest in Sasco male hamsters, but biliary
cholesterol (mol%) was lower in the males than in the females (4.2-4.5% vs. 6.1-7.1%) regardless of age. The
cholesterol saturation indices were higher in the Sasco females than the corresponding males; these values were lower in the Sasco hamsters than the Charles River animals, regardless of age or sex. The male Sasco hamsters had a higher total biliary
bile acid concentration (98.9 mg/mL) than the Sasco females (58.9 mg/mL) and the Charles River animals (24.6 mg/mL for males and 38.2 mg/mL for females). The percentage of
chenodeoxycholic acid in bile was significantly lower, and the percentage of
cholic acid was higher in all females as compared to males.(ABSTRACT TRUNCATED AT 250 WORDS)