Effects Of Dexamethasone Combined With Inhalation Of High Concentration Hydrogen On Treatment Of Paraquat Poisoning In Rats

ObjectiveTo study effects of dexamethasone combined with inhalation of high concentration hydrogen on treatment of paraquat poisoning in rats,and to find a new way and method for the treatment of paraquat poisoning.MethodsSeventy eight weeks old male SD rats were randomly devided to five groups?n=14?,control?Con?group,paraquat?PQ?group,paraquat+dexamethasone?PQ+DEX?group,paraquat+hydrogen?PQ+HY?group,paraquat+dexamethasone+hydrogen?PQ+DEX+HY?group.Each group was further divided into two parts,the experimental sampling?n=8?,m-ortality rates observing?n=6?.Group Con received 1ml normal saline intraperitoneal inj-ection,and 2.5ml normal saline were given intraperitoneal injection after 30min and 24h.PQ group was given 30mg/Kg paraquat?diluted to 1ml?intraperitoneal injection,and2.5ml normal saline were given intraperitoneal injection after 30min and 24h;group PQ+DEX was given 30mg/Kg paraquat?diluted to 1ml?by intraperitoneal injection,and2.5ml 50mg/Kg dexamethasone were given intraperitoneal injection after 30min and 24h;PQ+HY group was given 30mg/Kg paraquat?diluted to 1ml?intraperitoneal injection,and2.5ml normal saline were given intraperitoneal injection after 30min and 24h;PQ+DEX+HY group was given 30mg/Kg paraquat?diluted to 1ml?intraperitoneal in-jection,and 50mg/Kg dexamethasone were given intraperitoneal injection after 30min and24h.Con group,PQ group,PQ+DEX group were given 79%N₂,21%O₂ inhaled 1h,3times a day after exposure 1h.And PQ+HY group,PQ+DEX+HY group were given42%H₂,21%O₂,37%N₂ inhalation 1h,3 times a day.Rats in experimental sampling part?n=8?were all killed after exposure to 48h,and the sample of plasma,lung tissue and bronchoalveolar lavage fluid,liver,kidney,lung wet to dry ratio and the tissue and organ coefficient were measured,HE staining was used to determine injury of groups of rat liver,kidney and lung,the concentration of paraquat in plasma and tissue spectrophotometric meter method.determination of serum group and the level of MDA,MPO and SOD of serum were tested with Kit,and bronchoalveolar lavage cell count,the content of LDH were tested with Kit;The biochemical detector were used for determination of serum ALT,AST,BUN,Cr.Results1.Comparing the activities of rats in each groupAfter modeling 24h and 48h,the state of group PQ+DEX+HY was better than that of other groups,especially the polypnea.2.Comparing the survival status of rats in each group48 hours after modeling,the survival rate of group PQ was 50%,PQ+DEX was 50%.In group PQ+HY,it was 66.7%,group PQ+DEX+HY was 100%.According to the survival curve,the survival time of the PQ+DEX+HY rats was longer compared to PQ group?P<0.05?.3.Comparing injury of lung,liver and kidney pathological results in 3 groupsBy HE staining and pathological score,all groups showed different degrees of damage of lung,liver and kidney.Among them,group PQ+DEX and PQ+DEX+HY were all better in alveolar congestion,edema and inflammatory cell infiltration degree than that of group PQ.All groups showed different degrees of liver injury.In group PQ+DEX,liver tissue appeared necrosis,and compared with that of group PQ,PQ+DEX+HY,it was hea-vier.Large quantities of renal tubular casts appeared in group PQ+DEX,the renal tissue and tubular casts were injuried more obviously compared with group PQ,PQ+DEX+HY.4.Comparison of lung injury index in 4 groupsCompared to group Con,MDA,MPO,wet to dry ratio,organ coefficient,alveolar lavage cell count,LDH and protein concentration in lung tissue of the other groups all increased?P<0.05?.And it increased most significantly in group PQ for MDA,MPO,wet to dry ratio,LDH and protein concentrationt.It increased lower in Group PQ+DEX,PQ+DEX+HY than that of PQ?P<0.05?;and for organ coefficient,it increased lower in group PQ+DEX+HY than PQ?P<0.05?.5.Comparison of liver injury index in each groupCompared with group Con,MDA and ALT in liver tissue of the other groups all increased?P<0.05?,which increased most significantly in group PQ+DEX.In group PQ,PQ+HY and PQ+DEX+HY it increased lower than PQ+DEX?P<0.05?.Compared with group Con,MPO and AST of group PQ,PQ+DEX and PQ+DEX+HY all increased?P<0.05?,and it increased more significantly in group PQ+DEX and PQ+DEX+HY than that of PQ?P<0.05?.It increased lower in group PQ+DEX+HY than that of PQ+DEX?P<0.05?.6.Comparison of renal injury index each groupCompared with Con group,NGAL,MPO and serum MDA in renal tissues of the other groups all increased?P<0.05?,which increased most significantly in group PQ+DEX.Compared with group Con,creatinine in renal tissues of group PQ+DEX increased?P<0.05?,while BUN of group PQ,PQ+DEX,PQ+DEX+HY all increased?P<0.05?,and that of group PQ+DEX increased most?P<0.05?.7.Comparison of SOD,MDA and MPO of serum in each groupCompared with Con group,serum SOD of the other groups all decreased?P<0.05?,which decreased most significantly in group PQ than that of PQ+DEX+HY?P<0.05?.And serum MDA and MPO of the other groups all increased?P<0.05?,which increased most significantly in group PQ?P<0.05?.8.Comparison of paraquat concentration in tissue and serum in each groupParaquat concentration in lung and serum of group PQ+DEX,PQ+HY,PQ+DEX+HY all decreased compared to PQ?P<0.05?.All groups showed no signifi-cant difference as for that of liver and kidney tissues?P<0.05?.Conclusion1.Dexamethasone combined with inhalation of high concentration of hydrogen alleviate the paraquat poisoning in rats with acute lung injury and prolonged the survival time in treatment of paraquat poisoning rats.Dexamethasone combined with inhalation of high concentration of hydrogen has a certain therapeutic effect on paraquat poisoning rats.2.High dose of dexamethasone aggravate the liver and kidney damage of paraquat poisoning rats,and the application of high concentration of hydrogen suppressed this situation.