Pathophysiology of hypoxia in mice infected with Plasmodium berghei

Pathophysiological significance of hypoxia in malarial infection was investigated in mice infected with Plasmodium berghei NK65. Intraperitoneal inoculation of mice with 1×107 parasitized red blood cells resulted in death of the hosts 6–7 days later. Anaemia of infected animals developed on day 4 after inoculation and oxygen affinity of whole blood, measured as P50 act pH, increased simultaneously. This change may be a physiological adaptive response to a reduction in oxygen delivery to the tissues to day 5. However, the blood oxygen supply on day 6 appeared to be deteriorating and this is thought to be an important factor contributing to the death of the host. The value of adenylate energy charge in red cells during malarial infection, however, was comparatively well-maintained. Allopurinol stimulated the multiplication of malaria parasites and seems to have induced collapse in host-parasite balance more rapidly. Decrease in blood pH and in blood oxygen transport may be important factors for the pathogenesis of the allopurinol-treated hosts.