Effect of the bile acid taurolithocholate on cell calcium in saponin-treated rat hepatocytes.
Neomycin was used to assess the involvement of Ins (1,4,5)P3 in the Ca2+ release from the endoplasmic reticulum induced by the bile acid taurolithocholate. In saponin-permeabilized rat hepatocytes, neomycin via its ability to bind Ins (1,4,5)P3 abolished the release of Ca2+ induced by added Ins (1,4,5)P3. In contrast, it did not alter the Ca2+ release initiated by the bile acid. In intact cells, neomycin had no effect on the [Ca2+]i rises promoted by taurolithocholate and vasopressin. It is suggested that the effect of taurolithocholate in liver is not mediated by Ins (1,4,5)P3 but results from a primary action on endoplasmic reticulum.
Combettes
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Unité de Recherche INSERM U.274, Université Paris-Sud Bât. 443, Orsay, France.
Dumont
M
M
Berthon
B
B
Erlinger
S
S
Claret
M
M
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002478:Cells, Cultured; D004987:Ethers / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000494:pharmacology; D015759:Ionomycin; D007700:Kinetics; D008095:Lithocholic Acid / Q000031:analogs & derivatives*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D009355:Neomycin / Q000494:pharmacology; D051381:Rats; D012503:Saponins / Q000494:pharmacology*; D013658:Taurolithocholic Acid / Q000494:pharmacology*; D014667:Vasopressins / Q000494:pharmacology
D004987:Ethers; D007295:Inositol Phosphates; D012503:Saponins; D014667:Vasopressins; D013658:Taurolithocholic Acid; D015759:Ionomycin; D008095:Lithocholic Acid; D015544:Inositol 1,4,5-Trisphosphate; D009355:Neomycin; D002118:Calcium