Effect of intranasal glucocorticoid on the pathological change of nasal mucosa in rats with allergic rhinitis.

Abstract

To investigate the influence of inhaled glucocorticoid on the pathological change of the nasal mucosa in allergic rhinitis. One hundred and eighty Sprague-Dawley (SD) rats were selected. According to the random number table, these animals were randomly divided into two groups: the control Group A and the experimental group. There were 60 rats in Group A and 120 rats in experimental group. First of all, the rats in experimental group were sensitized by intra-peritoneal injection with ovalbumin (OVA), enhanced and local stimulated. Next, the rats in the experimental group were randomly divided into B and C groups. The number of rats in each group was 60. Group B still had the intranasal dropping on each side with OVA in the same volume and concentration twice a week. The rats in Group C also had the intranasal dropping on each side with OVA in the same volume and concentration twice a week. But, at the same time, these animals had fluticasone propionate (FP) nasal spray each side 50 microl/per day. While doing intra-peritoneal injection with physiological saline in the same volume and intranasal dropping on the rats in normal Group A. Ten rats from each group were randomly selected to be killed at the end of first, second, fourth, eighth, twelfth and sixteenth weeks after treatment. One from the ten rats in each group was used for micro-vascular casting of nasal mucosa, and the remaining nine were used for pathological examination. The model of the rats in experimental group was established successfully. After allergen stimulation, the nasal mucosa showed metaplasia of the goblet cells, epithelial denudation, inflammatory cells infiltration especially eosinophils, hyperplasia of the number of gland and density of micro-blood vessels. The capillary became netted. Cilia of epithelial shed to different extent and were uneven, and the layers of reticular formation of basal membrane became thick, and collagen deposition and fabric hyperplasia were seen under the electron microscope. In Group B, due to continuously contact with allergen, the mucosa remodeling enhanced. In Group C, glucocorticoid controlled the symptoms of allergic rhinitis better, but the cilia of epithelial shed, metaplasia of the goblet cells, inflammatory cells infiltration, hyperplasia of gland and micro-blood vessels, collagen deposition and fabric hyperplasia also could be seen in rat nasal mucosa. The pathological change of the nasal mucosa was found in allergic rhinitis. If the allergen was continuously contacted, the pathological change aggravated. Glucocorticoid could control the symptoms of allergic rhinitis better and reverse the mucosa pathological change to some extent, but it could not retro-converse or repair the nasal mucosa while the irreversibile change had occurred.