Effects of 5β-chol-3-en-24-oic acid, and lithocholic acid and its sulfates on prostaglandin E2 output in perfusion of the rat colon

The effects of bile salts on the output of prostaglandin E2(PGE2) were studied in rats by colonic perfusion. Bile salts and their concentrations in infusates were as follows; chenodeoxycholic acid sodium salt (CDCNa), sulfolithocholic acid disodium salt (SLCNa) and sulfotaurolithocholic acid disodium salt (STLCNa) were at 1 mmol/1, lithocholic acid sodium salt (LCNa) was at 0.6 mmol/1, 5β-chol-3-en-24-oic acid sodium salt (A3Na) was at 0.006 mmol/1, and sulfoglycolithocholic acid disodium salt (SGLCNa) was at 0.8 mmol/1. Median values of PGE2 outputs were 40.9, 52.4, 65.5, trace, 7.6, 9.8 and 9.8 pg/10 min/cm in the CDCNa, LCNa, Λ3Na, SLCNa, STLCNa, SGLCNa and control groups, respectively (control vs CDCNa, LCNa, Λ3Na, SLCNa group, p< 0.01 by median test). There was such a dissociation in PGE2 output and electrolyte concentration in the perfusates that high concentration of Na+ and Cl- ions was observed only in the SGLCNa group (p< 0.01 by t-test compared with the control group), whereas in the remainder of the groups substantial net movement of electrolytes and water was not observed. Light microscopy showed no evidence of morphological damage in any group. These results indicated that CDCNa, LCNa and Λ3Na increased PGE2 outputs in the colon at low concentration without functional or morphological changes.