Regulating effects of different doses of insulin on serum ILª²1¦Â and ILª²10 in early stage in severely scalded rats

    WANG Yunª²Chuan, GAO Feng, JIA Chiª²Yu, ZHANG Wanª²Fu, TANG Chaoª²Wu, HU Daª²Hai

    PLA Center of Burns, Xijing Hospital, Department of Physiology, School of Basic Medicine, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To determine the possible effects of different doses of insulin on the proª²inflammatory cytokine ILª²1¦Â and the antiª²inflammatory cytokine ILª²10 in early stage of severe burn in rats. METHODS: Male Spragueª²Dawly rats (30% TBSA, full thickness burn) were randomly divided into 2 groups to receive either normal saline only (n=14, with intraª²peritoneal injection of 40 mL/kg normal saline, group A) or normal saline plus different doses of insulin (n=42, with intraª²peritoneal injection of 40 mL/kg normal saline plus subcutaneous injection of 1, 3 or 5 IU/kg insulin respectively, group B1, B2, B3). In addition, 7 rats without thermal injury were subjected to normal control group (group N). The outcome measures encompassed the serum glucose, blood pressure, serum ILª²1¦Â and ILª²10 in rats at 6 and 24 h after scald and different treatments. RESULTS: The serum glucose increased quickly in rats after scald, which was demonstrated in group A to a range of (10.7¡À1.8) mmol/L by 6 h postª²scald. Insulin decreased the serum glucose in a doseª²dependent manner in rats of group B1, B2 and B3. And insulin at a dose of 3 IU/kg body weight reduced the serum glucose to a range of (6.0¡À0.8) mmol/L in rats at 6 h after thermal injury, which was almost eqeal to the normal range of (5.1¡À0.6) mmol/L (P>0.05). Meanwhile, insulin at this dose improved the blood pressure of scalded rats by keeping the blood pressure at a stable condition similar to the normal. Insulin significantly decreased the serum ILª²1¦Â in a doseª²dependent manner in scalded rats. It was partially showed after administration of insulin of 3 IU/kg serum ILª²1¦Â was (54.0¡À8.6) ng/L and (46.8¡À6.8) ng/L, much lower than that without insulin administration in rats at 6 and 24 h after thermal injury (P<0.01). Insulin could increase the serum ILª²10 in scalded rats. In comparison with group A, the most significant increase of serum ILª²10 was seen by application of 3 IU/kg insulin as (45.5¡À5.2) ng/L in rats 24 h after scald (P<0.01 vs group A). CONCLUSION: Our data provided an insight that insulin might attenuate the inflammatory cascade response by decreasing the proª²inflammatory cytokine ILª²1¦Â and increasing the antiª²inflammatory cytokine ILª²10, thereby keeping or restoring the systemic homeostasis after severe burn. The best administration dose of insulin in early burn stage should be determined by normalizing serum glucose. ......