Insulin resistance in peripheral tissues after a burn injury

The glucose uptake of a perfused, skin-covered preparation of muscle taken from the rat was altered by prior burn injury to the animal. Animals receiving an 8% deep burn to the back 24 hours prior to testing had a glucose uptake (5.9 +/- 0.85 microM/100 gm/min) which was depressed compared with control nonburned preparations (8.4 +/- 0.34 microM/100 gm/min) (P less than 0.025) at low insulin concentration (35 microU/ml). Higher insulin concentrations (160 microU/ml and 16 microU/ml) produced significant increases in the glucose uptake of both the burned and control animals. At the highest insulin level (16 microU/ml), there was no significant difference between burned and control animals. Preparations from animals burned five days prior to study showed a glucose uptake which was not decreased as compared with control animals at the low level of insulin (35 microU/ml) (7.4 +/- 0.62 microM/100 gm/min), but higher levels of insulin (160 microU/ml and 16 microU/ml) failed to produce a significant increase in glucose uptake (8.4 +/- 0.64 microM/100 gm/min and 8.6 +/- 0.92 microM/100 gm/min, respectively). The values differed significantly (P less than 0.05) from control preparation (11.5 +/- 0.54 microM/100 gm/min) at the insulin level of 16 microU/ml. Two different patterns of altered sensitivity to increased insulin concentrations were noted, depending on the stage of injury. The altered metabolic status of peripheral tissues does contribute to the insulin resistance pheonomenon observed after a burn injury.