Effect Of Histamine On Proliferation Of Airway Smooth Muscle Cells And The Expression Of ERK MRNA And CyclinD1 MRNA In Asthmatic Rats

Objective To investigate the effect of histamine on proliferation of airway smooth muscle cells in bronchial asthmatic rat and investigate the effect of histamine on the expression of ERK mRNA and CyclinD1 mRNA.MethodsPart oneThe model of asthmatic rat was made by ovalbumin(OVA) sensitization and excitation for 4 weeks. Lung tissue HE stating and image analysis to judge whether the airway remodeled. Primary culture of normal and asthmatic ASMCs were established.ASMCs were treated with different density histamine and then subdivided into 5 groups based on the interventions:(1)Normal control group; (2)Asthmatic model group;(3) 0.1mmol/L Hist group;(4) 0.3mmol/L Hist group; (5) 0.5mmol/L Hist group. The proliferations of ASMCs were examined by cell cycle analysis and MTT colorimetric assay. 0.5mmol/L Hist was selected as the density for the part two.Part twoPrimary culture of normal and asthmatic rats ASMCs were established.ASMCs were treated with 0.5mmol/L Hist based on part one and ERK inhibitor PD98059, and then subdivided into 4 groups based on the drug interventions: Normal control group; (2)Asthmatic model group; (3) 0.5mmol/L Hist group; (4)PD98059+Hist group; The proliferations of ASMCs were examined by MTT colorimetric assay, The expression of ERK1/2 mRNA and cyclinD1 mRNA were detected by RT-PCR. RESULTSPart one(1)After Lung tissue HE stating and image analysis, the asthmatic rats have formed airway remodeling.(2)Compared with nomal control group, the percentage of S+G2/M phase and absorbance A value of MTT in asthmatic model group, 0.1mmol/L Hist group,0.3mmol/L Hist group and 0.5mmol/L Hist group,increased significantly(P<0.01).Part two(1)Compared with nomal control group, absorbance A value of MTT in asthmatic model group, PD98059+Hist group and 0.5mmol/L Hist group,increased significantly(P<0.01). Compared with 0.5mmol/L Hist group, absorbance A value of MTT in PD98059+Hist group,decreased significantly(P<0.01). Compared with asthmatic model group, absorbance A value of MTT MTT in PD98059+Hist group, increased nonsignificantly(P>0.05).(2)Compared with nomal control group, the ratios of A values of ERK1/2 mRNA and CyclinD1 mRNA in asthmatic model group, PD98059+Hist group and 0.5mmol/L Hist group,increased significantly(P<0.05). Compared with 0.5mmol/L Hist group, the ratios of A values of ERK1/2 mRNA and CyclinD1 mRNA in PD98059+Hist group,decreased significantly(P<0.05).Compared with asthmatic model group, the ratios of A values of ERK1/2 mRNA and CyclinD1 mRNA in PD98059+Hist group,increased nonsignificantly(P>0.05).The same tendency of CyclinD1 mRNA and ERK mRNA was observed in each groups.CONCLUSIONS(1)Hist may further promote ASMCs proliferation of asthmatic rat.Hist may have density dependent to promote proliferation of ASMCs.(2)Hist induced proliferation of ASMCs may be involved in the ERK1/2 mRNA and CyclinD1 mRNA activation.(3)Except the ERK signal channel,other signal channel may be involved.