Effects of inhaled glucocorticoid on fear stress-induced rat models with asthma

Objective To determine the effect of negative moods on ovalbumin(OVA) in allergic rat models by examining cytokines and natural killer(NK) cells in peripheral blood, neurokinin A receptor(NK2-R) in the lung and observe the differentials during inhaled glucocorticoid inhalation. Methods Thirty-two healthy male SD rats were divided into 4 groups, group A as the control group, group B as the allergic group, group C as the fear-stressed-allergic group, group D as the glucocorticoid inhalation treatment and fear-stress-allergic group.The allergic rat models were established by OVA.Forced swimming test was performed at the same time in group C and group D, and glucocorticoid inhalation was given at the same time as OVA challenge in group D. Airway peak pressure was measured with four-lead graph system, HE staining was used to observe the inflammation of the lung , the level of NK cells in peripheral blood was detected by flow cytometry, the cytokines IL-4, IFN-γ levels in the serum were determined by enzyme-linked mmune sorbent assay, NK2-R mRNA level was evaluated by transcription-quantitative. Results The levels of IL-4 and airway peak pressure in group C were higher than those in group B and group A (all P<0.05); the level of IFN-γ in the serum and the number of NK cells in peripheral blood in group C diminished compared with group B and group A (P<0.05); the expression of NK2-R mRNA in the lungs in group C was higher than that in group B(P<0.05); while in group D airway peak pressure, IL-4 level in the serum and the expression of NK2-R mRNA in the lungs were lower than those in group C(all P<0.05); the levels of IFN-γ in the serum and the number of NK cells in peripheral blood in group D were higher than those in group C (all P<0.05). Conclusions Negative moods may aggravate the inflammation reactions in the respiratory tract of the asthmatic rats, which may affect the balance between Th1/Th2 cytokines, reduce the number of NK cells in the peripheral blood, and enhance the expression of NK2-R in the lung tissues. The glucocorticoid inhalation may correct Th1/Th2 cytokine imbalance, decrease the expression of NK2-R mRNA in the lungs, and increase the number of NK cells in the peripheral blood. Key words: Bronchial asthma; Negative mood; Glucocorticoid; Rat