Abstract: AIM:To explore whether the difference in the amount of chloroquine
(CQ) accumulated in CQ resistant (CR) and in CQ sensitive (CS) P.berghei is
involved in the infected erythrocytes (RBC) or in the parasites. METHODS:The
concentration of CQ in infected RBC and parasites following ig administration of CQ
to CS and CR infected mice was determined by HPLC method (extra standard).
RESULTS:3 h after 4.06 mg/kg and 400 mg/kg administration, the accumulation of CQ
in both infected RBC was similar, but in CR was 54. 0% and 42. 1% less than in CS
(P < 0. 001) respect ively. The CQ accumulation in CS 3 h and 7 h after ig
administration of CQ 400mg/kg was similar (0. 780±0. 128 nmol/protein and 0. 760±
0. 180 nmol/mg protein), while in CR the CQ-accumulation was higher at 7 h than
that at 3h after CQ administration (0. 452±0. 079 nmol/mg protein and 0. 559±0.
124 nmol/mg protein P < 0. 02). CONCLUSION: The low CQ accumulation in CR is
attributable to the parasite rather than to the infected RBC, and CR was not found
to excrete CQ more rapidly than CS.

Key words: Plasmodium berghei .chloroquine, accumulation, excrete, HPLC