[The curative effect of inhaled vitamin A with corticosteroid on rat after asthmatic pneumonia and its influence on TSLP expression].

Objective: To study the alteration of thymus matrix lymphocyte generator (TSLP) and change of the Th factor in the course of disease development, and to analyze the curative effect of inhalation of Vitamin A (VA) with corticosteroid for the treatment of asthmatic pneumonia.

Methods: Asthmatic pneumonia models were prepared by challenging rats with inhalation of ovalbumin for 4 weeks, and rested for 1 week. The treatment with VA and corticosteroid inhalation for 1 week was followed. The rat thymus and lung specimen were examen by histochemical and immunofluorescence staining.

Results: After 4 - 5 weeks of stimulation, there were more TSLP-positive cells and alveolar macrophages (AM) found in thymus and lung tissue of asthmatic group, the cell proliferation in spleen and thymus was obvious, and blood Th factors elevated. The inflammation within the lung tissue aggravated gradually. In VA group, the expression of TSLP and Th2 factors were all lowered at the 4th week. The TSLP expression slightly increased at the 5th week, and the cell proliferation within T-cell zone of spleen and thymus was strong at first and weakened later. Alveolar microphages (AM) increased significantly and the inflammation in the lung subsided gradually at the 5th week. In the hormone group, TSLP and Th2 factors expression in both thymus and lung were decreased at the 5th week, while the cell proliferation in thymus and lung was gradually increased. The quantity of AM was decreased, whereas the inflammation of the lung was increased gradually at the 5th week.

Conclusion: During asthmatic period elevated TSLP expression was accompanied by Th2 type responses while VA and corticosteroid both suppressed TSLP and Th2 factors expression. VA alone promoted T lymphocyte proliferation as well as the antigen elimination function by AM, after ceasing the usage, the lung inflammation abated gradually. In contrast, after ceasing the use of corticosteroid, inflammation aggravated.