Objective: To observe the effect of acupuncture on serum IgE level, the degranulation of mast cells, the release of histamine and serotonin, and the expressions of phosphorylated tyrosine-protein kinase Lyn and Syk (p-Lyn, p-Syk) in skin tissue in rats with urticaria, as well as analyze the mechanism of acupuncture in the prevention and the treatment of urticaria.
Methods: SD male rats were randomly divided into normal control, model control, medication and acupuncture groups (n＝10 in each group). The anti-ovalbumin serum was used to establish urticaria model. Rats of the medication group received gastric lavage of Loratadine (0.1 mg/100 g). In the acupuncture group, bilateral "Xuehai" (SP10) and "Quchi" (LI11) were punctured perpendicularly, about 2 to 4 mm in depth, and the needles were retained for 30 min. The treatment was given consecutively for 14 days in the two treatment groups. H．E. staining was adopted to observe the morphological changes of skin tissue, ELISA to determine the total IgE level in serum, the toluidine blue staining to observe the degranulation of mast cells in local skin tissue and the immunohistochemistry to determine the expressions of histamine and serotonin as well as the the expressions of p-Lyn and p-Syk.
Results: Compared with the normal control group, the epidermis of the model control group was significantly thickened, the dermis was swollen, the inflammatory infiltration of small vessels was serious and the mast cells were swollen and deformed, with blurred edge and exfoliated granules. Additionally, in the model control group, the serum IgE level was significantly higher (P<0.05), the expressions of histamine and serotonin, as well as p-Lyn and p-Syk proteins in local skin tissue were significantly increased (P<0.05). Compared with the model control group, in the acupuncture group and the medication group, the epidermis was slightly thickened, the dermis got slightly edema, the inflammatory cells were presented occasionally and the degranulation of mast cells were reduced. Besides, the serum IgE level was significantly decreased (P<0.05), the expressions of histamine and serotonin, as well as the p-Lyn and p-Syk were significantly reduced (P<0.05). There was no significant difference in each index between the acupuncture group and the medication group (P>0.05).
Conclusion: Acupuncture at LI11 and SP10 is applicable in the treatment of urticaria. This therapy inhibits the type Ⅰ hypersensitivity and the mast cell degranulation, which may be related to the regulation of p-Lyn and p-Syk protein expressions in the locus coeruleus skin tissue.
Keywords: Acupuncture; Histamine; IgE; Mast cells; Serotonin; Urticaria; pLyn; pSyk.