Effect of Low Dose of Hydrocortisone on Serum Inflammatory Cytokines in Pulmonary Acute Lung Injury Rat

Objective To explore the effect of low dose of hydrocortisone on serum inflammatory cytokines in pulmonary acute lung injury(ALI)induced by Escherichia coli(E.coli)in rat.Methods ALI models were induced by intratracheal E.coli injection,then 58 rats were randomly divided into hydrocortisone group(HC,28 rats)treated with hydrocortisone(5 mg/kg,intraperitoneally)and control group(C,30 rats)treated with normal saline(intraperitoneally).In the normal control group(N,18 rats),normal saline was used by intratracheal(3 mL/kg) saline was administered intratracheally and intraperitoneally.Mechanical ventilation was applied at 12,24,36 hours.The blood gas and blood pressure were measured.After the experiment,animals were killed,TNF-α,IL-8 and IL-10 in serum were measured by ELISA.Results 1.At 36 h,the incidence of ARDS in group HC had no differences compared with that in group C(P0.05).At other times,the mortality rates of ALI and ARDS were similar between group HC and group C(Pa0.05).2.The pa(O2)/FiO2 in group HC and group C were significantly lower than that in group N(Pa0.01).The blood pressure in group HC was higher than that in group C(Pa0.05).Except at 36 hours,there was no significant differences between group HC and group N(P0.05),at other times there were significant differences(Pa0.01).3.The levels of TNF-α,IL-8 and IL-10 in serum in group HC and group C were significantly higher than those in group N(Pa0.05),TNF-α in group HC was significantly lower than that in group C(Pa0.05),IL-8 in group HC was lower than that in group C at 36 hours(P0.05),there was no significant difference of IL-10 between group HC and group C(Pa0.05).Conclusions Low dose of hydrocortisone can decrease the production of pro-inflammatory cytokines and maintain blood pressure in rats with ALI induced by E.coli.