Calcium anti-ionophoretic effect of some calcium channel blockers in rat liver mitochondria.
Beyond their classical action on calcium channels, some calcium channel blockers also exhibit a calcium anti-ionophoretic effect. We studied this effect on respiratory control and Ca2+ fluxes in a mitochondrial model to compare calcium antagonists chosen among three clinical classes: vascular, cardiac, and mixed effects. Synthetic calcium ionophore A23187 decreases respiratory control and modifies Ca2+ fluxes. We show that calcium antagonists partially restore the parameters altered by A23187. By calculating the percentage of restoration, we found that vascular drugs exhibit a strong anti-ionophoretic effect, cardiac drugs exert no significant effect, and mixed calcium antagonists exert an intermediate effect. Thus, it appears possible to link the intensity of calcium anti-ionophoretic effect with the clinical interest of a calcium antagonist.
Ubeaud
G
G
Laboratory of Biophysics, Faculty of Pharmacy, Marseilles, France.
Chauvet-Monges
A M
AM
Monti
J P
JP
Tillement
J P
JP
Crevat
A
A
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D066298:In Vitro Techniques; D007478:Iontophoresis; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats
D002121:Calcium Channel Blockers; D000001:Calcimycin; D002118:Calcium