Objective: To observe the effect of acupoint injection at "Yingxiang"(LI 20) and "Yintang"(GV 29) on nasal allergic reactions and the expression of histamine receptor H 1 and H 4 in nasal mucosa of allergic rhinitis (AR) rats, so as to reveal its mechanism underlying improvement of AR.
Methods: SD rats were randomized into normal, model, non-acupoint injection and acupoint injection groups (n=8 in each). The AR model was established by intraperitoneal (i.p.) injection of mixture of ovalbumin, aluminium hydroxide gel and normal saline (once every other day, for 7 times), and nasal drip of ovalbumin (on the following day of i.p.for 7 days). The mixture solution of lidocaine, dexamethasone (DXM) and transfer factor (0.1 mL/acupoint or non-acupoint) was injected into bilateral LI 20 and GV 29 in the acupoint injection group, or into the non-acupoints (about 5 cm below the armpit on both sides, and the middle point between the left "Houhai"[GV 1] and "Huantiao"[GB 30]), on the 1st , 5th, 9th, and 13th day after modeling. Symptoms of sneezing, nasal discharge, nose-rubbing, etc. were scored after the treatment. The expression levels of H1 R and H4 R proteins and genes in the nasal mucosa tissue were determined using immunohistochemistry and quantitative real-time PCR, respectively.
Results: Compared with the normal group, the symptom score and the expression levels of H1 R, H4 R proteins and genes in nasal mucosa were significantly increased in the model group (P<0.05). After acupoint injection for 4 times, the symptom score and the expression levels of H1 R, H4 R proteins and mRNAs were significantly down-regulated in the acupoint injection group relevant to the model group (P<0.05). There were no significant differences between the non-acupoint and the model groups in the abovementioned indexes (P>0.05), suggesting a specificity of the effect of acupoint injection.
Conclusion: Acupoint injection can relieve the allergic symptoms of AR rats, which may be related to its effects in down-regulating the over expression of H1 R and H4 R proteins and genes in the nasal mucosa.
Keywords: Acupoint injection; Allergic rhinitis; Histamine H 1 receptor; Histamine H 4 receptor; Nasal allergic symptoms.