title: The chemotherapy of rodent malaria, XXXI. The effect of some metabolic inhibitors upon chloroquine-induced pigment clumping (CIPC) in Plasmodium berghei.
abstract: The effect of metabolic inhibitors upon chloroquine-induced pigment clumping in intraerythrocytic Plasmodium berghei was studied in vitro. Oligomycin and venturicidin competitively inhibit the process with 'Ki' values of 0.18 and 0.41 mumol/l. DCCD, an agent thought to act upon a mitochondrial site close to that affected by oligomycin and venturicidin, causes pigment clumping in the absence of chloroquine ('Km' value 4.7 mumol/l). It is suggested that, after being concentrated in the cytoplasm by Fitch's high-affinity site, chloroquine interacts with a mitochondrial site, and this interaction initiates the pigment clumping process. Comparison of the effects of the ionophores 2,4,-dinitrophenol, monensin, and valinomycin indicates that a H gradient is involved at some stage in chloroquine-induced pigment clumping.
mesh_terms: D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology*; D002738:Chloroquine / Q000494:pharmacology; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D051379:Mice; D008985:Monensin / Q000494:pharmacology; D009840:Oligomycins / Q000494:pharmacology; D010860:Pigments, Biological; D010962:Plasmodium berghei / Q000187:drug effects*; D014634:Valinomycin / Q000494:pharmacology; D014698:Venturicidins / Q000494:pharmacology
chemical_list: D000963:Antimetabolites; D009840:Oligomycins; D010860:Pigments, Biological; D014698:Venturicidins; D014634:Valinomycin; D004024:Dicyclohexylcarbodiimide; D002738:Chloroquine; D008985:Monensin