ABSTRACT
Objective To investigate the potential roles of chromogranin A in pathogenesis of asthmatic inflammation,and to assess the regulation of montelukast on chromogranin A expression.Methods The rat asthma model was established with ovalbumin,and they were allocated to three groups,named asthma group,control group and montelukast group.The expressions of chromogranin A protein and mRNA at lung tissue were detected by immunohistochemisty or real-time PCR methods,and positive expression intensity of chromogranin A protein was assayed by optical density.The correlation between chromogranin A protein and mRNA was also analyzed.Results The expression levels of chromogranin A protein in asthma group(0.34 ±0.05 optical density)was significantly higher than that in control group (0.21 ±0.06 optical density)(P<0.01 ).The expression levels of chromogranin A mRNA in asthma group (4.02 ±0.95 relative quantity value)was significantly higher than that in control group(P<0.01 ).The expression levels of chromogranin A protein in montelukast group(0.28 ±0.04 optical density)was dramatically lower than that in asthma group (0.34 ±0.05 optical density)(P<0.05),while there were no statistical significance of chromogranin A mRNA(3.67 ±0.78 relative quantity value)between those two groups(P>0.05 ).But levels of mRNA was positively correlated with protein of chromogranin A (r=0.635,P<0.01).Conclusion Expressions of chromogranin A protein and mRNA at lung tissue were increased in asthmatic rats,and the results demonstrated that chromogranin A perhaps participated in the pathogenesis of asthma inflammation,but this function of chromogranin A protein could be down regulated by montelukast.