Histopathologic changes in two mouse models of asthma.

BACKGROUND No studies to date have compared mouse models of asthma by evaluating airway histopathology. OBJECTIVE To compare 2 such models by studying chronic histopathologic changes of the airways using light and electron microscopy. METHODS Twenty-one male BALB/c mice were divided into 3 groups: a nebulization group sensitized via an intraperitoneal injection of 10 microg ovalbumin on days 0 and 14 and exposed to 2.5% aerosolized ovalbumin 3 days a week over the subsequent 8 weeks; an intranasal group sensitized via 2 intraperitoneal injections of 100 microg ovalbumin on days 0 and 14 and administered an intranasal dose of 500 microg ovalbumin on days 14, 27, 28, 29, 47, 61, 73, 74, and 75; and a control group that received nothing. Airway histopathologies were evaluated. RESULTS Basement membrane, epithelium, and subepithelial smooth muscle layer thicknesses and mast and goblet cell numbers were significantly higher in the nebulization group than in the control group. With the exception of mast cell numbers, these parameters were also significantly higher in the intranasal group than in the control group. On comparing the intranasal and the nebulization group, goblet cell numbers were significantly higher in the former and mast cells in the latter. CONCLUSION Both models replicated all the structural parameters of asthma except for mast cell numbers in the intranasal group (no significant difference with respect to the control group). Our findings do not provide sufficient evidence that one protocol is superior to the other. Larger studies are needed to compare different asthma protocols.