title: Cyclosporin A protects liver cells against phalloidin. Potent inhibition of the inward transport of cholate and phallotoxins.
abstract: Cyclosporin A at concentrations of more than 10 nM protects isolated hepatocytes against the action of phalloidin. Cyclosporin A at 100 nM inhibits the uptake of demethyl[3H]phalloin by 50%, and at 5 microM also that of [14C]cholate. This inhibition is independent of the preincubation period and is not reversed by washing the cells. With a 30-60-fold excess of cyclosporin A, affinity labeling of plasma membrane proteins using 12 microM [3H]isothiocyanatobenzamido cholate was reduced to 40-60% of the control. These findings indicate that transport inhibition by cyclosporin A in liver cells cannot be explained by simple competition on the level of the membrane protein(s) involved.
mesh_terms: D000345:Affinity Labels / Q000378:metabolism; D000470:Alkaloids / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D019826:Cholic Acid; D002793:Cholic Acids / Q000378:metabolism*; D003524:Cyclosporins / Q000494:pharmacology*; D017879:Isothiocyanates; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009842:Oligopeptides / Q000494:pharmacology*; D010590:Phalloidine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013861:Thiocyanates / Q000378:metabolism
chemical_list: D000345:Affinity Labels; D000470:Alkaloids; D002793:Cholic Acids; D003524:Cyclosporins; D017879:Isothiocyanates; D009842:Oligopeptides; D013861:Thiocyanates; D010590:Phalloidine; C000880:desmethylphalloin; C041686:3'-isothiocyanatobenzamidecholic acid; D019826:Cholic Acid