title: [Accumulation and effluxion of chloroquine in chloroquine-sensitive and chloroquine-resistant Plasmodium berghei].
abstract: OBJECTIVE
  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) respectively. The CQ accumulation in CS 3 h and 7 h after ig administration of CQ 400 mg/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 3 h after CQ administration (0.452 +/- 0.079 nmol/mg protein and 0.559 +/- 0.124 nmol/mg protein P < 0.02).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Parasitic Diseases, Chinese Academy of Preventive Medicine, Shanghai 200025.
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Chang
authors.forename: B
authors.initials: B
authors.lastname: Yang
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000378:metabolism*; D002738:Chloroquine / Q000378:metabolism*; D004351:Drug Resistance; D004912:Erythrocytes / Q000378:metabolism; D008288:Malaria / Q000097:blood*; D051379:Mice; D010962:Plasmodium berghei / Q000378:metabolism*
chemical_list: D000962:Antimalarials; D002738:Chloroquine