| Abstract: | Bromosulfophthalein and papaverine have beendemonstrated to inhibit biliary lipid secretion withoutaffecting secretion of bile salts in normal rats,so-called uncoupling. Bromosulfophthalein inhibits the capacity of intracanalicular bile saltmicelles to induce biliary lipid secretion, andpapaverine inhibits vesicular transport within thehepatocyte. We compared the effects ofbromosulfophthalein and papaverine on biliary lipid secretion in normalSprague-Dawley rats and Eizai hyperbilirubinuria rats.The fatty acyl chain saturation in biliary lecithinincreased during bromosulfophthalein infusion and decreased during papaverine infusion inSprague-Dawley rats. Bromosulfophthalein had no effecton biliary lipid secretion in Eizai rats, whilepapaverine induced uncoupling. The degree of fatty acylchain saturation in biliary lecithin was unchangedduring bromosulfophthalein infusion, but decreased withpapaverine in Eizai rats. We deduce that selection ofbiliary lecithin species occurs at various points in the lipid transport pathway at intracellularand intracanalicular sites. |
