Effects Ofacupuncture On Ocular Surface Damage And The Apoptosis Of The Lacrimal Gland In Rabbit Dry Eye Model

Objective:To investigate the effect of acupuncture on ocular surface and lacrimal gland of rabbit in aqueous deficient dry eye model.Also to explore the possible mechanism of acupuncture on dry eye model rabbits by subcutaneous scopolamine.Methods:24 healthy New Zealand white rabbits were divided into blank group,model group and acupuncture group randomly,8 rabbits in each group.Blank group do not accept any treatment.Model group and acupuncture group were treated with subcutaneous injections of scopolamine hydrobromide,4 times a day with the dose of 2.0mg·kg-1 until the end of the trial,when the acupuncture group was also treated with acupuncture,once a day for fourteen days.3 groups were examined Schirmer I test(SIT),tear film break-up time(BUT)and corneal fluorescein staining(CFS)at different stages,and morphological changes of lacrimal gland under light and electron microscope.Immunohistochemical method was used for the detection of protein levels of apoptosis-related factors of Bax,Bcl-2,Fas and FasL in lacrimal gland of all rabbits.Also the content of acetylcholine(ACh)in lacrimal gland was detected by enzyme-linked immunosorbent assay.Results:1.SIT:Between the acupuncture group and model group,the SIT was significantly different(P<0.05)on day 4,7,14.At the same time,compared with that before experiment,SIT had no significant difference(P>0.05)on day 14 in acupuncture group.2.BUT:Between the acupuncture group and model group,the BUT was significantly different(P<0.05)on day 7,14.While compared with that before experiment,BUT had no significant difference(P>0.05)on day 14 in acupuncture group.3.CFS:Between the acupuncture group and model group,the CFS was significantly different(P<0.05)on day 7,14.But when compared with before acupuncture,any period of after acupuncture of the acupuncture group showed significant difference on CFS,and the score was the highest at day 4,and then showed a downward trend.4.Morphology observation of lacrimal gland:Normal lacrimal gland tissue in blank group had no obvious cell expansion and contraction.In model group,lacrimal gland epithelial cells atrophy,intracellular substances decreased,with a large number of lymphocytes infiltration.Columnar epithelial cells of lacrimal gland was expansion in acupuncture group,with abundant cytoplasm,small amount of lymphocyte infiltration,no obvious glandular atrophy.5.Apoptosis-related factors in lacrimal gland:Occasionally positive expression in the blank group,and a large number of light yellow to brown yellow granular cells were seen in the model group;a few pale yellow to brown yellow granule cells were observed in the acupuncture group.Meanwhile the number of lacrimal epithelium cells with Bax,Fas and FasL positive expression was significantly decreased than that in the model group(P<0.05,t=3.773,3.244,1.633;p=0.001,0.041,0.001).But when it compared with blank group,there was no significant difference of Bax/Bcl-2 and Fas/FasL positive expression in acupuncture group(P>0.05,p=1.0/1.0,0.715/0.675).6.Ach content in lacrimal gland:The content of Ach in lacrimal gland of acupuncture group was significantly higher than that of the model group,P<0.05;while the difference between the acupuncture group and the blank group was not significantdifferent,P>0.05.Conclusion:1.Scopolamine hydrobromide from subcutaneous injection produced dry eye rabbit model successfully,and long-term stability.2.Optical and electron microscope showed the lacrimal gland of model group with epithelial cells atrophy,intracellular substances decreased,and a large number of lymphocytes infiltration.But with abundant cytoplasm,closely arranged and active cell activities in acupuncture group,close to that of the blank group.3.Local acupuncture has good effect on rabbit in aqueous deficient dry eye model,can effectively promote lacrimal gland secretion and tear film stability,improve the status of cornea.Meanwhile acupuncture could promote Ach release,restrain the apoptosis and gland atrophy of lacrimal gland tissue of dry eye rabbit model,and then improve metabolism,thereby increasing the tear secretion.