CHANGES OF BLOOD OXYGEN AFFINITY IN FANSIDAR-TREATED MICE INFECTED WITH PLASMODIUM BERGHEI

Changes of blood oxygen affinity in mice infected with Plasmodium berghei and treated with Fansidar (20 mg/kg body weight sulfadoxine and 1 mg/kg body weight pyrimethamine orally) were observed. When 5-weeks-old male mice were inoculated intraperitoneally with 107 of P. berghei-infected red cells and treated with Fansidar on day 5 after inoculation, 67% of the animals survived. Parasitemia decreased and abnormal values of glycolytic intermediates began to recover following Fansidar administration. However, hemoglobin content still decreased on day 2 of the treatment, and methemoglobin fraction increased on days 1, 2, 3 and 4. Blood oxygen affinity increased markedly on days 2 and 3. These findings suggested aggravation of the host's hypoxic state on day 2 of the treatment.