Neutropenic rat model

Methods for generating a neutropenic rat model were previously described³³. Briefly, cyclophosphamide was administered intraperitoneally in doses of 100 mg/kg of body weight at 4 days before burn (−4 PBD) and 75 mg/kg of body weight at 1 day before burn (−1 PBD). A 30% TBSA thermal burn was performed at day 0 (0 PBD). Granulocyte counts were taken for non-infected rats to assess the effects of cyclophosphamide at 4 days and just before burn, and at 1 PBD. All rats were monitored closely for 24 hours, and blood samples were collected at 1 PBD and they were euthanized at 2 PBD (Fig. 6C). As demonstrated previously³⁴, cyclophosphamide therapy effected a reduction in the mean WBC count from 12,700 WBCs per µL on day 0 to 470 WBCs at day 5 and maintenance of the count at the lower level throughout the therapeutic period (day 5 to 8). Reduction in total WBC count was accompanied by a reduction in granulocytes. On day 0, the mean granulocyte count was 1,905 granulocytes per µL, and on day 5 through 8, it was less than 50 granulocytes per µL. No special precautions were taken with the rats during the period of neutropenia, with no signs of infection and no deaths observed in neutropenic rats.