Effect of twice-daily oral administration of hydrocortisone on the bile acids composition of gallbladder bile in dogs.

OBJECTIVE: To investigate the effects of twice-daily oral administration of hydrocortisone on the bile acids composition of gallbladder bile in dogs. ANIMALS: 6 placebo-treated control dogs and 6 hydrocortisone-treated dogs. PROCEDURES: Dogs received hydrocortisone (median dose, 8.5 mg/kg) or a gelatin capsule (control group) orally every 12 hours for 84 days. Gallbladder bile samples were obtained via percutaneous ultrasound-guided cholecystocentesis from each dog before (day 0 [baseline]), during (days 28, 56, and 84), and after (days 28p, 56p, and 84p) treatment for differentiated quantification of unconjugated bile acids and taurine-conjugated and glycine-conjugated bile acids via high-performance liquid chromatography-tandem mass spectrometry.
RESULTS: Treatment with hydrocortisone for 84 days resulted in significant and reversible increases in the concentrations of unconjugated bile acids (ie, cholic, chenodeoxycholic, and deoxycholic acids) and a significant and reversible decrease in the concentration of total taurine-conjugated bile acids, compared with baseline or control group values. Treatment with hydrocortisone had no effect on bile concentrations of glycine-conjugated bile acids. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, hydrocortisone administration caused reversible shifts toward higher concentrations of the more hydrophobic unconjugated bile acids (chenodeoxycholic acid and deoxycholic acid) and toward lower concentrations of the amphipathic taurine-conjugated bile acids in gallbladder bile. These data suggest that similar bile acids changes could cause major alterations in gallbladder structure or function over time in hypercortisolemic dogs.