Effect of acupuncture on expression of transfer growth factor-β1 in lacrimal gland of rabbits with dry eye

Abstract

To observe the effect of acupuncture on expression of transforming growth factor-β1(TGF-β1) in lacrimal gland of rabbits with dry eye, so as to explore its underlying mechanism in improving dry eye. Healthy male New Zealand rabbits were randomly assigned to 5 groups (n=6 in each group), namely, blank group, model group, western medicine group, acupuncture group and sham acupuncture group. The dye eye rabbit model was estabilished by subcutaneous injection of Scopolamine Hydrobromide solution for 21 days. After modeling, rabbits in the western medicine group were treated with Flumirone eye drops in their eyes 3 times a day, one drop each time. Rabbits of the acupuncture group reveived electroacupuncture(4 Hz/20 Hz, 1 mA) at "Cuanzhu"(BL2) and "Tongziliao"(GB1) for 15 min, and received acupuncture at "Jingming"(BL1), "Taiyang" (EX-HN5) and "Sizhukong"(TE23) for 15 min, once a day. Rabbits of the sham acupuncture group received blunt acupuncture at the surface of the same acupoints once a day. All the treatments were conducted for 14 days. The changes of tear flow, tear film break-up time (BUT) and lacrimal gland morphology in each group were observed. The expression of TGF-β1 protein and mRNA in lacrimal gland were detected by Western blot and quantitative real-time fluorescence PCR respectively. Following modeling, except for the blank group, the tear flow and BUT in other 4 groups decreased significantly (P<0.01). Compared with their own pretreatment, the tear flow and BUT in western medicine group and acupuncture group increased after the treatment (P<0.05). Compared with the model group, the tear flow and BUT increased in the western medicine group and the acupuncture group(P<0.05). Atrophic lacrimal epithelial cells and the stroma of mucous membrane infiltrated by lymphocytes and plasma cells were found in rabbits of the model group and the sham acupuncture group. By contrast, in the western medicine group and the acupuncture group, the structure of lacrimal epithelial cells was basically normal, and the infiltration of lymphocytes and plasma cells were scattered in the stroma of mucous membrane. In comparison with the blank group, the expression of TGF-β1 protein and mRNA in lacrimal gland were significantly up-regulated in the model and sham acupuncture groups (P<0.01). Compared with the model group, the expression of TGF-β1 protein and mRNA were significantly down-regulated in the western medicine and acupuncture groups (P<0.01, P<0.05). Acupuncture intervention can increase tear flow and BUT in rabbits with dry eye, which may be related to the regulation of TGF-β1 expression in lacrimal gland.