[Studies on the establishment of malarial animal model of short-term relapse. IV. Short-term relapse in rhesus monkeys infected with sporozoites of Plasmodium cynomolgi].
The present paper reports that the short-term relapse could be artificially made by the application of the experimental method, and thus we established the monkey model of the short-term relapse. According to the experimental design, when the parasitemia was detected in rhesus monkeys infected with sporozoites of Plasmodium cynomolgi, a combined therapy of pyronaridine 6 mg/kg body weight, artemether 10 mg/kg and chloroquine 20 mg/kg once daily for 3 days was carried out to clear the erythrocytic parasite and then the short-term relapse was observed in the animal follow-up for 100 days. The combined therapy was given again when relapse occurred. One onset of relapse occurred on 47 days after therapy in monkey M194 infected with sporozoites 11 x 10(3). In M195 infected with sporozoites 55 x 10(4), relapses occurred for 3 times on 30, 37 and 51 days respectively after medication, but during a follow-up period of 200 days, no relapse was shown in M192 and M193 infected with sporozoites 50 and 55 x 10(2), respectively. The results showed that the frequency of the short-term relapse was relative to the sporozoites inoculation, and sporozoites less than 11 x 10(3) were not suitable for making short-term relapse in animal model. No long term relapse could be seen in all the 4 monkeys until 400 days. Under existing conditions that the relapse was generally explained with hypnozoite assumption, the establishment of animal model of short-term relapse could be tenable.(ABSTRACT TRUNCATED AT 250 WORDS)
Zhang
J X
JX
Institute of Parasitic Diseases, Chinese Academy of Preventive Medicine, Shanghai.
Lin
B Y
BY
Pan
Y R
YR
Zheng
H
H
Tang
W Z
WZ
Chen
Y D
YD
Xu
B
B
D000818:Animals; D000962:Antimalarials / Q000008:administration & dosage*; D000077549:Artemether; D037621:Artemisinins; D002738:Chloroquine / Q000008:administration & dosage*; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D004912:Erythrocytes / Q000469:parasitology; D008253:Macaca mulatta; D008288:Malaria / Q000188:drug therapy*; D009287:Naphthyridines / Q000008:administration & dosage*; D016789:Plasmodium cynomolgi; D012008:Recurrence; D012717:Sesquiterpenes / Q000008:administration & dosage*
D000962:Antimalarials; D037621:Artemisinins; D009287:Naphthyridines; D012717:Sesquiterpenes; D002738:Chloroquine; D000077549:Artemether; C027871:pyronaridine