Abstract: Objective To establish immediate asthma model in two strains of guinea pigs (Zmu-1:DHP and DHP) with ovalbumin (OVA), and find out histamine receptor (H1R, H2R) gene expression difference and their effect on pulmonary function. Methods Two strains of Zmu-1:DHP and DHP guinea pigs were divided into two model groups (MW and MP) and two control groups (BW and BP) respectively. Guinea pigs of model groups were sensitized with OVA, as control groups were treated with normal saline. on the first and 14th day, each guinea pig of model groups were given OVA. On the 28th day,dynamic lung compliance (Cdyn) and airwayresistance (Raw) of every guinea pig were recorded from 0 to 8 minutes after exposure to OVA. Then guinea pigs were sacrificed, lung tissue were examined by H1R, H2R mRNA expression test and immuohistochemistry (IHC) analysis. Results After exposure to OVA, guinea pigs of Zmu-1:DHP and DHP model groups (MW and MP) had lower C_dyn and higher Raw changes than control groups (BW and BP) from 0 to 8 minutes and with the maximum Cdyn and Raw change at third minute. Group BW had more sensitive reaction than Group BP. QPCR analysis revealed, group MW had higher mRNA expression of H1R and H2R than group BW (P<0.05). Obvious inflammatory cell infiltration of lung tissues were observed by HE staining in model groups (MW and MP), but didn’t in control groups (BW and BP). By IHC, the H1R and H2R expression were observed in smooth muscle of bronchus and vessel. Conclusion In immediate asthma model, H1R and H2R express mainly in smooth muscle of bronchus, its sensitive may have high relation to expression of H1R.

Key words: Asthma, Ovalbumin (OVA), Histamine receptor, Pulmonary function, Guinea pig