CHARACTERIZATION OF SC2644-INDUCED CHOLERESIS IN DOG - EVIDENCE FOR CANALICULAR BICARBONATE SECRETION

  • 1 January 1978
    • journal article
    • research article
    • Vol. 206  (1) , 190-197
Abstract
The biliary clearances of [14C]erythritol (Cery) and [3H]mannitol (Cmann) were measured simultaneously in dogs, first during choleresis induced by varying doses of sodium taurocholate and then by SC 2644 [.beta.-(2,4-dimethoxy-5-cyclohexylbenzoyl) propionic acid]. Cery increased equally with the increases in bile flow induced by both compounds. Mannitol entry into bile was partially restricted; .DELTA.Cmann/.DELTA.bile flow averaged 0.66 and 0.68 for taurocholate- and SC 2644-induced flows, respectively. A common canalicular site of origin of the increased bile flow was suggested. Electrolyte composition was quite different in the increments. The bicarbonate concentration in the SC 2644-induced increment of bile (65.8 .mu.eq/ml) was 3 times higher than that associated with bile stimulated by taurocholate. SC 2644- and taurocholate-induced biles were virtually isosmotic. These results in concert with other observations suggest a canalicular mechanism for bicarbonate entry into the biliary tree. Stimulation by SC 2644 of ductal chloride bicarbonate exchange cannot be excluded.