The prostaglandin response to cholesterol feeding by the rabbit gallbladder in vitro.

Eleven rabbits (five female, six male) were fed a high (2%) cholesterol diet for 2 weeks. Twelve control rabbits (six female, six male) were fed standard rabbit chow. As expected, the cholesterol feeding raised serum and bile cholesterol concentrations and increased the lithogenic indexes. The gallbladders were harvested, and the mucosa and serosa were separately exposed to arachidonic acid in an in vitro incubation chamber at 37 degrees C. Cholesterol feeding stimulated the rates of synthesis of PGI2, but this effect was limited to the serosa (and not the mucosa) of gallbladders from female (but not male) animals. In contrast, cholesterol did not induce any changes in PGE biosynthesis.