Biliary excretion of radioactivity after intravenous administration of 3H-1, 25-dihydroxyvitamin D3 in man. Issue 11 (November 1985)

• Record Type: Journal Article
• Authors: Ledger, J E; Watson, G J; Ainley, C C; Compston, J E
• Is Part Of: Gut. Volume 26:Issue 11(1985)
• Page Start: 1240
• Page End: 1245
• Publication Date: 1985-11
• Subjects: Gastroenterology -- Periodicals; 616.33
• DOI: 10.1136/gut.26.11.1240
• Languages: English
• ISSNs: 0017-5749

Abstract

Abstract : Biliary radioactivity excretion was studied in 10 patients with postcholecystectomy T-tube drainage after intravenous administration of 3H-1, 25-dihydroxyvitamin D3. The mean +/- SD radioactivity excreted in T-tube bile expressed as a percentage of the administered dose was 18.9 +/- 10.7% per 24 hours. After correction for incomplete bile collection the value obtained was 28.8 +/- 12.8%. The mean chloroform solubility of the biliary radioactivity increased from 17.0 +/- 8.4% to 69.4 +/- 15.1% after incubation with beta-glucuronidase. High performance liquid chromatography of chloroform extracts of bile revealed that most of the eluted radioactivity was more polar than 1, 25(OH)2D3. The percentage radioactivity eluting as 3H-1, 25(OH)2D3 increased from approximately 2.4 +/- 1.9 to 16.2 +/- 8.0 after incubation with beta-glucuronidase. We conclude that significant amounts of intravenously administered 3H-1, 25(OH)2D3 are excreted in bile, mostly as more polar metabolites. The increase in free 3H-1, 25(OH)2D3 after incubation with beta-glucuronidase indicates that glucuronides of 1, 25(OH)2D3 are present in bile.