PLASMODIUM-FALCIPARUM GLUTATHIONE METABOLISM AND GROWTH ARE INDEPENDENT OF GLUTATHIONE SYSTEM OF HOST ERYTHROCYTE

Plasmodium falciparum parasites grew normally in glutathione (GSH)-dep leted normal and G6PD-deficient (Mediterranean variant) erythrocytes ( RBC), Growth inhibition was observed only at less than approximately 6 -12% residual GSH. Parasites studied separately with the Sendai virus technique synthesized GSH de novo and regenerated reduced GSH 10-20 ti mes faster than non-parasitized RBC. Electron spin resonance measureme nt of Tempol reduction indicated that the ability to reduce free radic als,vas restricted to the parasite, The marked efflux of oxidized GSH was mainly derived from the parasite, In conclusion, parasites are end owed with powerful and host-independent mechanisms which de novo synth esize or regenerate GSH and allow undisturbed parasite development in GSH-depleted RBC, (C) 1998 Federation of European Biochemical Societie s.