Effects Of Histamine On Acute Lung Injury Induced By Endotoxin In Chicken

The experiment aimed to investigate the effects of two histamine receptor antagonists,ehlorphenamine maleate and cimetidine,on acute lung injury induced by endotoxin in chickens.Then,it was indicated that the role of endogenous histamine on acute lung injury induced by endotoxin.Metheds:One hundred and twenty 20-days chickens were randomly divided into five groups:(1) control group(CG),(2) endotoxin group(EG),(3) Chlorphenamine maleate group(CM), (4)Cimetidine group(CMT),(5)Chlorphenamine galeate and Cimetidine group (CMC).Every group was use the corresponding drugs treatment respectively for 15 days.At 1st,5th,10th,15th day,10 chickens were randomly taken from each group and measured the rectal temperature at 0 h,2h,4h,6h,after endotoxin injected.Fasting and free drinking at 4th,9th,14th night,7 chickens were randomly taken from each group on next day.The birds was killed by blooded and blood was choosed for measured the blood indexes.The lung,heart and liver of each chicken was collected and fixed in Neutral buffer formalin,carnoy's and ultra cold freezer.Paraffin sections were made.Hematoxylin and eosin staining,toluidine blue staining and acridine orange staining were used.The score criterion of pathology changes and number of mast cells(NMC) were measured with an automated computerized image analyzer.1.(1) Acute experiment,the temperature of CM decreased significantly lower than that of EG at 2 h,4h(P＜0.05),But the temperature of CMT and CMC decreased significantly lower at 2h(P＜0.01).(2) Choric experiment,the temperature of CM decreased significantly at 10 day(P＜0.05),the CM and CMC decreased significantly at 15 day(P＜0.05). 2.(1) The NMC of lung parenchyma in EG is significantly lower than that of other groups(P＜0.01) at 5th day,besides CM was significantly lower than that of CMC,CMT and CG(P＜0.05).There was no significant difference at 10th day.CM is significantly lower than that of CMT at 15th day(P＜0.05).(2) The NMC in mucosa bronchus of lung in EG is significantly lower than that of CM,CMT(P＜0.01), CMC,BG(P＜0.05)at 5th day.At 10th and 15th NMC of EG is significantly lower than that of CM,CMT,CMC.(3)The contents of histamine in lung of CMC is lower than that of EG,CM and CMT.At 5h day,CMC was significantly lower than that of CM and CMT(p＜0.05).At 10th day,EG was significantly higher than that of CMC and CG. At 15th day,EG was significantly higher than that of CMC(p＜0.01),CM and BG(p＜0.05).3.(1) The WBC,LYM,MON,GRA of EG were higher than other groups,but no significant difference at 5th.At 10th,15th dayCMT was significantly higher than that of other groups(p＜0.05).(2) The degree of lung injury of EG was significantly bigger than other groups all the time(p＜0.01),CMC was significantly lower than that of CM and CMT at 5th(p＜0.01),but at 10th,15th,CMC was significantly lower than that of CM(p＜0.01) and CMT(p＜0.05).Conclusion:Histamine receptor antagonists can reduce the lung injury induced by endotoxin.Chlorphenamine Maleate was better than cimetidine,then,when they were used together,the effect was best.It can indicate that histamine through H₁ and H₂ receptors effected endotoxin-induced lung injury,but mainly through H₁ receptor.