ABSTRACT
Objective To explore the impact of glucocorticoid on coagulation through administrating on rats with smoke inhalation.Methods Totally 150 male S-D rats were randomly (random number) divided into 5 groups:control group (ambient air inhalation),smoke group (smoke inhalation for 30 min),smoke+high dosage methyl prednisolone group(MP 40 mg/kg,intraperitoneal injection,s+HMP group),smoke+medium dosage MP (4 mg/kg) group (s+MMP group),smoke+low dosage MP (0.4 mg/kg) group (s+LMP group) (all n=30).Survival rates were calculated 24 h after smoke inhalation.Lung tissues were collected for histopathology and wet to dry (W/D) ratio.Arterial blood was collected for blood gas test.Coagulation factors in lung and plasma were tested.Results Survival rates of three MP groups were markedly improved compared with the smoke group (all P＜0.05),and was significantly higher in the medium dosage group(85.17％) than those in the low and high dosage groups (65.73％ and 60.07％,all P＜0.05).The W/D ratio and blood gas test were markedly improved in the high and medium groups (all P＜0.05).Tissue factor (TF) and thrombin-antithrombin complex (TAT-c) in bronchoalveolar lavage fluid (BALF) increased dramatically after SI (P＜0.01,P=0.005) with a remarkable drop of factor Ⅱ (F Ⅱ) (P=0.007),all of which were attenuated by MP with dosage dependence.The mRNA expression of TF increased dramatically after SI and recovered significantly with MP administration,while the expression of thrombomodulin (TM) recovered in the opposite direction with MP,all of which were in a dosage dependent manner.TF,fibrinogen (FIB),TAT-c increased significantly in plasma after smoke inhalation (P＜0.01,P=0.027,P=0.005).F Ⅷ ％ increased with MP administration and TF was raised by high dosage MP compared with the smoke group.FIB and TAT-c were decreased in all MP groups,which were significant higher in the high and middle dosage groups.The change of TM and endothelial cell protein C receptor (EPCR) in circulation were similar with FIB or TAT-c with or without MP.Protein C (PC％) and antithrombin (AT Ⅲ ％) dropped dramatically after SI,high and middle dosages of MP could restore the activity significantly,while low dosage would restore AT Ⅲ ％ but not PC％.Conclusions Glucocorticoid can significantly improve local and systemical coagulation disorder caused by smoke inhalation,and high-and medium-dosage hormones are effective.The regulation of hormones on the coagulation system is an important mechanism in the treatment of smoke inhalation induced lung injury.