Inhibition of deoxycholate-induced secretion of fluid in jejunum by mixed miceilar solutions. S.

Deoxycholate, a secondary unconjugated dihydroxy bile salt, is produced by the bacterial degradation of primary trihydroxy bile salts. This dihydroxy bile salt may occur in the small intestinal lumen of man in conditions of bacterial overgrowth; it induces fluid secretion into the lumen, and has been implicated in the pathophysiological mechanisms responsible for certain types of infantile diarrhoea (Harries and Sladen, 1972). We are currently investigating the influence of micellar solutions on the effects of deoxycholate on fluid and electrolyte transport in rat jejunum, using an in vivo closed-loop technique. Both 2 5 and 5 mmol/l. deoxycholate produced secretion of water, sodium, and chloride, and this effect persisted when the bile salt was solubilized in pure bile salt micelles (using 15 and 25 mmol/l. taurocholate). Mixed taurocholate (15-20 mmol/l.) micelles con-taining 0 25, 0*75, and 10 mmol/l. oleic acid were prepared, and 2- 5 mmol/l. deoxycholate was solubilized in each of the solutions. With increasing concentrations of oleic acid there was a concomitant reduction in the secretory effects of deoxycholate, and at 10 mmol/l. net absorption occurred in all the animals tested. Oleic acid (10 mmol/l.) emulsions had no effect on the secretory effects of deoxycholate. These observations may indicate that the clinical effects of deoxycholate in man are dependent on its physicochemical state in the intestinal lumen, the efficiency of pancreatic lipolysis, and the amount and type of dietary fat. REFERENCE Harries, J. T., and Sladen, G. E. (1972). The effects of different bile salts on the absorption of fluid, electrolytes, and mono-saccharides in the small intestine of the rat in vivo. Gut, 13, 596. Plasma nephelometry after oral fat loading in children with normal and abnormal jejunal morphology. M. F. Robards introduced by B