Acute effects of cholestatic and choleretic bile salts on vasopressin- and glucagon-induced hepato-biliary calcium fluxes in the perfused rat liver.
The effects were investigated of the choleretic bile salt glycoursodeoxycholate (G-UDCA) and of the cholestatic bile salt taurochenodeoxycholate (T-CDCA) on changes in perfusate Ca2+, glucose and oxygen and in bile calcium and bile flow induced by the administration of (a) vasopressin, (b) glucagon and (c) glucagon plus vasopressin together to the perfused rat liver [Hamada, Karjalainen, Setchell, Millard & Bygrave (1992) Biochem. J. 281, 387-392]. G-UDCA itself increased the secretion of calcium in the bile several-fold, but its principal effect was to augment each of the above-mentioned metabolic events except glucose and oxygen output; particularly noteworthy was its ability to augment the 'transients' in bile calcium and bile flow seen immediately after the administration of vasopressin with or without glucagon. T-CDCA, by contrast, produced opposite effects and attenuated all of the parameters measured, and in particular the transients in bile calcium and bile flow. The data provide evidence of a strong correlation between calcium fluxes occurring on both the sinusoidal and the bile-canalicular membranes and that all are modifiable by glucagon, Ca(2+)-mobilizing hormones and bile salts.
Hamada
Y
Y
Division of Biochemistry and Molecular Biology, School of Life Sciences, Faculty of Science, Australian National University, Canberra.
Karjalainen
A
A
Setchell
B A
BA
Millard
J E
JE
Bygrave
F L
FL
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004357:Drug Synergism; D005704:Gallbladder / Q000187:drug effects / Q000378:metabolism*; D005934:Glucagon / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D013655:Taurochenodeoxycholic Acid / Q000494:pharmacology*; D014580:Ursodeoxycholic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D014667:Vasopressins / Q000494:pharmacology*
D014667:Vasopressins; D013655:Taurochenodeoxycholic Acid; C024033:glycoursodeoxycholic acid; D014580:Ursodeoxycholic Acid; D005934:Glucagon; D002118:Calcium