Sensitivity of Asexual Blood Stages Of . Plasmodium Berghet (Nk 65) to Chloroquine

Abstract

The erythrocytic developmental cycle of Plasmodium berghei can be conveniently divided into the ring, tropho-zoite and schizont stages based on morphology. The sensitivity and effect of chloroquine on density-gradient isolated fractions of each of these stages was investigated using the plasmodial strain P.berghei (NK65), a rodent model as an experimental tool. This plasmodial strain was found to be routinely lethal in infected mice in the absence of administered therapeutic levels of chloroquine. P.berghei infected blood was separated into the various developmental stages using discontinuous Percoll gradient centrifugation. The various stage-isolated fractions were found to be infective and sensitive to these same levels of chloroquine. However chloroquine was found to show insignificant differential sensitivity with regards to the developmental stage of berghei (NK 65) strain.