Effect of electroacupuncture on the morphology of prostate and degranulation of mast cells in rats with chronic nonbacterial prostatitis

Abstract

To observe the effect of electroacupuncture (EA) on the morphology of prostate and degranulation of mast cells in prostate of rats with chronic nonbacterial prostatitis (CNP). Male SD rats were randomly divided into sham operation group, model group and EA group, with 8 rats in each group. CNP model was established by surgical castration combined with 17-β estradiol injection once daily for 30 days. EA was applied to "Zhongji" (CV3), "Guanyuan" (CV4) and bilateral "Dahe" (KI12) for 20 min, once daily for 8 days. The mechanical pain threshold of scrotum skin area was tested before modeling, after modeling and after intervention. The pathological morphology of the prostate was observed by HE staining. Collagenous fiber was observed by Masson staining. The infiltration of mast cells was observed by toluidine blue staining. The contents of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) in prostate were determined by ELISA. The protein expression levels of tryptase and transforming growth factor β1 (TGF-β1) in prostate were detected by Western blot. A normal appearance with little inflammatory cell infiltration was observed in the prostate of the sham operation group. Gland atrophy, epithelial destruction, hyperemia and edema, diffuse inflammatory cell infiltration and visible collagen fiber deposition were observed in prostate of the model group. The degree of infiltration of inflammatory cells and collagen fiber deposition were reduced in the EA group. Compared with the sham operation group, mechanical pain threshold was decreased (P<0.01), while the collagen volu-me fraction (CVF) of prostate, the degranulated rate of mast cells, the protein expression levels of tryptase and TGF-β1, and the contents of IL-6 and TNF-α were increased (P<0.01) in the model group. Following EA intervention, compared with the model group, the mechanical pain threshold was increased (P<0.01), CVF of the prostate, the degranulated rate of mast cells, the protein expression levels of tryptase and TGF-β1, and the contents of IL-6 and TNF-α were decreased (P<0.05, P<0.01) in the EA group. EA can relieve pain and reduce inflammation and fibrosis of prostate in CNP rats, which may be related to inhibiting the degranulation of prostate mast cells and down-regulating the expression of inflammatory factors and TGF-β1.