Intervention Effect and Mecha-nism of Wumei Pill on Chronobio-logical Rhythm Disorder in Chronic High Intraocular Pressure Model Rats
OBJECTIVE To investigate the intervention effect of Wumei Pill on chronobiological rhythm disorder in a chronic high intraocular pressure(IOP)rat model.METHODS A total of 30 rats were used to establish the chronic high IOP rat model using scleral venous occlusion.They were randomly divided into the model group(MG)and Wumei Pill group(WM),with a control group(CG)undergoing sham surgery.The WM group rats were orally administered Wumei Pill decoction 9 g/kg daily,while CG and MG groups were given an equal volume of 0.9%sodium chloride solution orally six times a week for four consecutive weeks.IOP was measured at 2:00,8:00,14:00,and 20:00 on the day after the last administration to evaluate the 24 h IOP rhythm.Retinal morphology was observed using hematoxylin-eosin(HE)staining after tissue collection.Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL)assay was used to detect retinal ganglion cell(RGC)apoptosis.Enzyme-linked immunosorbent assay(ELISA)was used to measure serum levels of melatonin(MT),cortisol(CORT),adrenocorticotropic hormone(ACTH),and corticotropin-releasing hormone(CRH)at 2:00.Western Blot was used to assess the expression level of the ipRGC-specific protein,melanopsin,in the retina.RESULTS(1)Retinal morphology:Retinal tissue structure was disrupted in MG group rats,with loose inner and outer nuclear layers and disorganized RGCs and significantly reduced numbers.The retinal tissue structure in the WM group was relatively clear and intact,with a slight loss of RGC.(2)RGC apoptosis rate:The RGC apoptosis rate was higher in the MG group than in the CG group(t=16.010,P=0.000),and lower in the WM group than in the MG group(t=-12.890,P=0.000),with statistically significant differences.(3)Diurnal IOP fluctuation:The IOP at each time point in the MG group rats was higher than that in the CG group(t2:00=16.600,t8:00=19.190,t14:00=16.230,t20:00=15.900,all P=0.000).The IOP at 2:00 and 8:00 was lower in the WM group rats than in the MG group(t2:00=-2.796,P=0.009;t8:00=-4.166,P=0.000),with statistically significant differences.The overall peak of IOP occurred at 2:00 in the rats,with a gradual decrease from 2:00 to 8:00,a significant drop from 8:00 to 14:00,and the lowest IOP at 14:00.(4)Chronobiological rhythm parameters:Serum MT expression was lower in the MG group rats than in the CG group(t=-7.480,P=0.000).Serum MT and CORT expression were higher in the WM group rats than in the MG group rats(tMT=7.136,tCORT=5.390,both P=0.000),while CRH expression was lower in the WM group than in the MG group(t=-3.144,P=0.004),all with statistically significant differences.(5)Melanopsin Protein:Retinal melanopsin protein expression was lower in the MG group rats than in the CG group rats(t=-16.127,P=0.000),and higher in the WM group rats than in the MG group rats(t=6.390,P=0.001),with statistically significant differences.CONCLUSIONS Chronic high IOP in rats for 28 days led to decreased melanopsin protein expression,decreased serum MT secretion at 2:00,increased diurnal IOP fluctuation,and induced RGC apoptosis.Wumei Pill,the principal prescription for alleviating the hypochondriac disease,may improve the chronobiological rhythm disorder in the chronic high IOP rat model and inhibit RGC apoptosis by mediating melanopsin protein expression.
万方数据
维普
