Objective:To detect collagen I synthesis activity in the vitreous of PVR induced by macrophages in rabbits. Methods:PC Ⅲ (Procollagen Ⅲ ) concentrations were measured by radioim- munoassay in the vitreous samples of 14 rabbit eyes with experimental PVR and 14 control eyes. Results:The mean PC Ⅲ concentration on the 7th day after macrophage injection as 257.58mu;g/L(range,236.04~266.88mu;g/L,n= 4)and significantly increased on the 14th day later. On the 28th day the mean concentration of PC Ⅲ as 912.23mu;g/L (range, 881.36~943.10mu;g/L ;n= 2). There was a significant difference between the 7th and the 14th, 21st of 28th day statistically(P<0.05). PC Ⅲ was not detected in control eyes. Conclusion:The PC Ⅲ level in the vitreous of rabbit eyes with experimental PVR increased significantly from the 7th to the 28th day after macrophages injection and is well consistent with the time course of scarring and the development of traction retinal detachment in the PVR model. (Chin J Ocul Fundus Dis,1996,12: 43-44)
Our previous experiments showed limited results of treatment with daunomycin when given at the inflammatory stage of proliferative vitreoretinopathy(PVR)induced by macrophages in rabbits.In the present study,we observed the inhibition of intraocular cellular proliferation in the same model by daunomycin which was injected in a dosage of 5mu;g 6 days after intravitreal macrophage injection,with 3H-thymidine autoradiography.The efficacy of daunomycin was also compared with that of triamcinolone,and combined triamcinlone and daunomycin.The retinal detachment occurred in 33.3%,16.1%,8.3%and 83.3%(P<0.01) of the eyes treated with daunomycin,triamcinolone,combined drugs and the control groups,respectively.Autoradiography revealed a singnificantly decreased number of labelled nuclei of proliferative cells on days 7 and 14 in daunomycin-treated eyes(compared to controls,18.8plusmn;3.2 vs 35.7plusmn;3.4;52.1plusmn;8.0 vs 81.3plusmn;14.6,P<0.01,respectively).Significantly decreased numbers of inflammatory cells and labelled cells were also noted in eyes treated with triamcinolone and combined drugs.The results suggest that daunomycin given at the proliferative stage,and triamcionlone given at the inflammatory stage of PVR,or combined drugs can prevent traction retinal detachment. (Chin J Ocul Fundus Dis,1994,10:229-231)
The stimulating effects of subretinal fluid (SRF) of 31 patients with rhegnmtoganous retinal detachment (among them 5 are recurrent) on the growth of fihroblasts were investigated. The results demonstrated that all samples of SRF showed stimulating effect in a variable degree.The range of proliferation-stimulating activity was from 86. 7% to 366.7% above the baseline.The stimulating ahility was mainly related to the degree of PVR and may be also related to the extent and clinical course of the detaehrnent. When stimulating rate was S0Y0 ,the dilution multiple of SRF was higher in recurrent patients than that in initiate ( P<0.01). (Chin J Ocul Fundus Dis,1993,9:11-13)
Objective To investigate the effect of hypericin on the activity of protein kinase C (PKC) in cultured human retinal pigment epithelium (RPE) cells in vitro.Methods RPE cells were cultured in standard medium with 10% serum concentrations containing 0.5 to 5.0 μmol/L hypericin with or without preincubation of phorbol 12-myristate 13-acetate (PMA). The activities of cytosolic PKC (c-PKC) and membranous PKC (m-PKC) were assayed by PKC kit. Results The original activities of c-PKC and m-PKC of RPE cells were (35.34±4.10) pmol·min-1·mg-1and (62.52±8.80) pmol·min-1·mg-1.The activity of c-PKC in RPE cells with PMA preincubation decreased rapidly in 5 minutes, with a subsequent slow decrease after 20 minutes and a decrease to 18% of the activity of c-PKC in RPE cells without PMA preinubation after 60 minutes. While the activity of m-PKC in RPE cells with PMA preincubation increased gradually after 5 minutes and reduced after reached the peak at 40 minutes, and then returned to baseline after 60 minutes, eventually decreased below 30% of the control group. When RPE cells were cultured with PMA for 48 hours, the activities of c-PKC and m-PKC were hardly detectable, while RPE cells were cultured with both PMA and hypericin, hypericin could counteract most of down-regulation by PMA. Conclusion Hypericin may inhibit the translocation of PKC in RPE cells,change the activity of PKC, promote the apoptosis of RPE cells likely,and then prevent proliferative vitreoretinopathy. (Chin J Ocul Fundus Dis,2003,19:55-58)
ObjectiveTo observe the longterm effect of suramin on the inhibition of proliferation of human retinal pigment epithelial (RPE) cells in vitro. MethodsRPE cells grown in 9 pieces of 96well plate (12 wells each plate) were divided into experimental and control group, with 6 wells in each group. The concentration of 0.1 ml RPE cells in each well is 5×104 cells/ml. After the change of the medium, RPE cells were treated with suramin (250 μg/ml) in experimental group while treated with nothing in the control group. The medium of the 2 groups were changed to the normal medium after 4 days. At the 1st, 2nd, and 4thday after the addition of suramin and at the 1st, 2nd, 3rd, 5th, 6th, 7th, 9th , 11th and 13th day after removing suramin, 1 plate was randomly selected to stop culturing, and the proliferation of RPE cells were detected by methyl thiazolyl tetrazolium (MTT) assay. ResultsUnder reversed microscope, RPE cells in control group were fused completely at the 7th day after inoculation. The extracellular space of RPE cells in experimental groups was larger than that in the control group, and remained unfused at the 13th day after inoculation. The inhibitory rate of proliferation of RPE cells at the first day after treated with suramin was 14.85% and increased to the highest 25.79% at the 4th day. The first day after the suramincontaining media was removed, the inhibitory rate decreased to 12.35%, and then raised gradually to over 20% at the 3rd to 5th day. Finally, the rate drop to 14.71%. ConclusionSuramin has the long-term effect on the inhibition of RPE cells induced by serum, especially the inhibitive effect after the remove of suramin, which indicates the specific double-peak inhibition during the whole process.(Chin J Ocul Fundus Dis, 2005,21:25-27)