| SHORT COMMUNICATION
|Year : 1996 | Volume
| Issue : 3 | Page : 191-193
Calcium blocking potencies of some antimalarials on isolated rat aortic strip preparation
PI Aziba, DT Okpako
The calcium channel blocking activities of equimolar concentration of chloroquine, amodiaquine, mepacrine, quinine and mefloquine were examined on the rat isolated aortic strip and compared with that of diltiazem, a classical organic Ca2+ channel blocker. All antimalarial drugs as well as diltiazem non-competitively inhibited the contractile effect of calcium chloride. They displaced response curve in a non-parallel fashion to the right with depressed maxima. Amon antimalarial drugs, chloroquine and amodiaquine were equipotent with Ic70 of 2.15(0.2 x 10-6 M, while mefloquine was the least potent (lc70 of 5.2(0.4 x 10-6 M) although chloroquine was at least 1,000 times less potent (on molar basis) than diltiazem as a Ca2+channel blocker in this preparation. It was concluded that antimalarial drugs possessed appreciable Ca2+ channel blocking activities, although much less than diltiazem.
P I Aziba
Source of Support: None, Conflict of Interest: None