Increased Hippocampal Glucocorticoid Receptor Expression and Reduced Anxiety-Like Behavior Following Tuina in a Rat Model With Allergic Airway Inflammation

Objective

This study aimed to explore the influence mechanism of Tuina on anxiety-like behavior in immature rats with allergic airway inflammation (AAI).

Methods

A total of 27 Sprague-Dawley male rats (aged ∼5 weeks) were divided randomly into control, AAI, and AAI with Tuina groups (9 rats per group). The anxiety-like behavior was assessed by an open field test and elevated plus-maze test. Allergic airway inflammation was assessed based on the pathological score of the lung, plasma ovalbumin-specific immunoglobulin E, interleukin 4, interleukin 5, and tumor necrosis factor-alpha levels. Glucocorticoid receptor (GR) messenger RNA and protein expression in the hippocampus and lung were detected by polymerase chain reaction and immunohistochemistry, respectively. Meanwhile, corticotropin-releasing hormone (CRH) messenger RNA in the hypothalamus, the plasma levels of adrenocorticotropic hormone and corticosterone were also determined respectively by polymerase chain reaction and enzyme-linked immunosorbent assay for hypothalamic-pituitary-adrenal axis (HPA) function.

Results

The AAI group had obvious anxiety-like behavior and hyperactive HPA axis, along with decreased GR expression in the hippocampus and lung. Following Tuina, AAI and the anxiety-like behavior were efficiently reduced, and the hyperactivity of HPA axis was efficiently inhibited, along with enhanced GR expression in the hippocampus and lung.

Conclusion

Glucocorticoid receptor expression in the hippocampus and lung was enhanced, and anxiety-like behavior was reduced following Tuina in rats with AAI.