[The expression and regulation of heme oxygenase-1 in asthmatic guinea pigs]

To explore the expression and pathogenic mechanism of heme oxygenase-1(HO-1) in asthma.

Two groups of guinea pigs (10 in each) were treated with the specific stimulator(hemin) and inhibitor(Sn-PP) of HO-1 respectively. Their effects on the levels of HO-1 activity, COHb, cGMP and IgE in serum or blood and lung tissues were compared with each other. Acute asthmatic group (AAG), dexamethasone-prevented group(DPG), stable asthmatic group, ovalbumin-sensitized group and normal control group(NCG) were also included. Lung tissues of tested animals were pathologically observed and immunohistochemically stained.

In the AAG and hemin stimulated group, the levels of COHb, cGMP and IgE were significantly increased with higher levels of activity and expression of HO-1 protein compared with the NCG (t = 4.575-10.188, P < 0.01). In DPG and Sn-PP inhibited groups, however, all measured parameters were markedly reduced compared with the AAG(P < 0.01). The other groups were normal.

The increased production and activity of HO-1 resulted in increases of endogenous CO and cGMP and promoted inflammation and immunoreaction in asthma.