Blood-stage malaria infection in diabetic mice

Infection of mice with blood-stage Plasmodium yoelii and P. chabaudi malaria induced hypoglycaemia in normal mice and normalized the hyperglycaemia of mice made moderately diabetic with streptozotocin (STZ). Injection of parasite supernatants induced hypoglycaemia accompanied by hyperinsulinaemia in normal mice, and in STZ-diabetic mice induced a profound drop in blood glucose and restored insulin secretion; however, severely diabetic mice (two injections of STZ) remained hyperglycaemic with no change in insulin levels. We conclude that malaria infection and parasite-derived molecules lower blood glucose concentration, but only in the presence of some residual pancreatic function. Diabetic mice were less anaemic, exerted a significant control of parasitaemia, and showed enhanced phagocytic activity compared with normal mice.