Effect Of Nebulized Ketamine On Expression Of Nitric Oxide Synthase, TNF-α, IFN-γ In Lung Of Asthmatic Rats

Objective To investigate the effect of nebulized ketamine inhalationon the expression ofTNF-α,IFN-γ,nitric oxide synthase(NOS) in lung ofasthmatic rats.Methods Forty Brown Norway rats (10-12 weeks) were randomlyassigned to five groups with eight animals each, control group(C),asthmagroup(A),and ketamine pretreated groups(K1,K2,K3).In groupA,K1,K2,K3,asthma was induced in two steps: receiving subcutaneousinjection of ovalbumia(OVA) 1mg and aluminum hydroxide 160mg in1ml of PBS,and then inhaling nebulized 1% OVA in PBS for 30 min. Ingroup K1,K2 and K3,the sensitized rats were exposed to 12.5mg/ml(K1group), 25mg/ml(K2 group), 50mg/ml(K3 group) of nebulized ketaminefor 30 min.Lung samples were taken and total RNA were isolated, TNF-α,IFN-γ,NOS mRNA were determined with RT-PCR. The rightlung was removed for microscopic examination.Results: There were acute airway inflammation changes in group A.Compared with group A, there was significantly less inflammation in thebronchial subnucosa and alveolar septum in group K1,K2 andK3.Compared with group C, the expression of TNF-α,IFN-γ,iNOSmRNA was significantly higher in group A(P＜0.01 ) Compared withgroup A, the expression of TNF-α,IFN-γ,iNOS was significantly less ingroup K1,K2and k3.There was no significant difference between groupK1,K2 and K3 in expression of eNOS mRNA. Expression of nNOS waslow in all groups.Conclusion: Inhalation of nebulized ketamine can restrain theexpression of TNF-α,IFN-γ,iNOS mRNA in lung in asthmatic rats andhas a protective effect on airway against inflammation and tissue damage.25mg/ml nebulized ketamine appears to be enough for satisfactoryclinical results.