Objective To investigate the effect of inducible nitric oxide synth ase (iNOS) or cyclooxygenase－2 (COX－2) on retinal neovascularization and its possible mechanism in oxygen－induced retinopathy （OIR） mouse model. Methods Retinal neovascularization was induced by oxygen with different concentration. The expression of iNOS, COX－2, matrix metalloproteinases 2 (MMP－2) and vascular end othelial growth factor (VEGF) in the retinae of experimental animals were analyzed by immunohistochemistry, realtime polymerase chain reaction and western blotting technologies. Results The inhibition of COX－2 or iNOS obviously attenuated retinal neovascularization and decreased the expression of VEGF and MMP－2. The iNOS inhibition decreased COX－2 expression, and vice versa. Conclusions COX－2 and iNOS may play a role in retinal neovascularization in OIR mouse model, which may act by regulating the expression of VEGF and MMP－2.
OBJECTIVE:To verify the safe dose of cephradine in intravitreal injection. METHODS:After injecting different doses of cephradine(100mu;g,200mu;g,250mu;g,300mu;g,400mu;g)into vitreous cavity of different group of rabbits the activities of the retinal enzymes (SDH,LDH )on different time (Id,3d, 7d ) were determined respectively, and the histological and ultrastructural changes of retinas were also observed simuhaneously. RESULTS:The activity of rellnal SDH and LDH was found to be decreased gradually with tbe icreasing of the dosage of intravitreal cephradine. The activities of SDH and LDH were found in the lowest level on tile 3rd and lsl day,but they recover to normal levels on tile 7th day after intravitreal in}eetion in 100mu;g,200mu;g groups,and still lower tban normal in the other groups. Histologically,retinal edema was found both in 100mu;g and 200mu;g groups,but degradation of retinal cells,and loss of cones and rods were round in the 250mu;g, 300mu;g and 400mu;g groups. CONCLUSION: The safe dose of intravitreal injection of cepbradlnc is 200mu;g. （Chin J Ocul Fundus Dis,1997,13:139-142 ）
ObjectiveTo investigate the effects of thrombospondin-1 active fragment (TSP-1) synthetical peptide VR-10 on proliferation and migration of rhesus choroidal-retinal endothelial (RF/6A) cell and the expressions of apoptosis relative genes in RF/6A cell. MethodsThe survival rate of RF/6A cell were detected by methyl thiazolyl tetrazolium, and migration ability was measured by transwell chamber after exposure to 1.0 μg/ml TSP-1 and synthetic peptide VR-10 (0.1, 1.0, 10.0 μg/ml) for different times (6, 12, 24, 48 hours). Caspase-3 and factor associated suicide (FAS) protein levels were measured by Western blot. The mRNA level of bcl-2 and FAS ligand (FASL) were measured by reverse transcription-polymerase chain reaction (RT-PCR). ResultsThe survival rate of RF/6A cells was determined by the treatment time and concentration of TSP-1(1.0 μg/ml) and the synthetic peptide VR-10 (0.1, 1.0, 10.0 μg/ml). The lowest survival ratio of RF/6A was 78% (P < 0.001) when cells were treated by 10 μg/ml synthetic peptide VR-10 after 48 hours. TSP-1 and synthetic peptide VR-10 could inhibit migration of RF/6A cells in transwell chamber (P < 0.001). 10.0 μg/ml synthetic peptide VR-10 had the strongest effect, 1.0 μg/ml TSP-1 was the next. Migration inhibition rate was increase with the increase of the concentration of VR-10 (P < 0.001). There was no significant differences between 0.1 μg/ml and 1.0 μg/ml VR-10 (P=0.114). Western bolt showed that RF/6A cell in control group mainly expressed the 32×103 procaspase-3 forms. To 10.0 μg/ml VR-10 treated group, it showed decreased expression of procaspase-3 (32×103) and concomitant increased expression of its shorter proapoptotic forms (20×103). Compared with control group, expression of FAS peptides were significantly increased in 10.0 μg/ml VR-10 treated group. Compared with control group, expression of FasL mRNA was significantly increased in 10.0 μg/ml VR-10 treated group(t=39.365, P=0.001), but the expression of bcl-2 mRNA was decreased(t=-67.419, P=0.000). ConclusionTSP-1 and synthetic peptide VR-10 had the ability to inhibit proliferation and migration of endothelial cell, and also induce apoptosis by increasing FAS/FASL expression and repressing bcl-2 expression.
Objective To inverstingate the effect of perfluorohexyloctane(F6H8)to the retina of rabbit eyes. Methods Fifteen vitrectomized New Zealand white rabbits were injectedF6H8(experiment group,12 rabbits ) and BSS(control group,3 rabbits) into vitreous cavity.Slit-lamp biomicroscopy and indirect ophthalmoscopy were performed pre- and postoperatively in all the eyes.Histopathological examination was done after the rabbits were sacrificed at the end of the study. Results A large clear balb was formed after intravitreal injection of theF6H8 in the vitreous was injected and no retinal detachment and cataract were found.The OPL was edematous and then thinned out in 4th week in experimental group.Degenerating cells was found in inner and outer nuclear layers.Cellular vaculoar degeneration was present in TEM. ConclusionF6H8 in vitreous cavity may cause significant side effects on retina,we could not recommend it to be used as an intraocular temponade.
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)
Purpose To investigate the effects of intervention with Tanakan on anterior ocular segment in diabetic retinopathy (DR) after retinal photocoagulation． Methods Prospective random controlled study was performed on 72 patients (72 eyes) with ultrasound biomicroscopy (UBM),by obtaining and quantitatively analyzing the changes of anterior ocular segment including anterior chamber, anterior chamber angle, ciliary body and choroids before and the 3rd day and the 7th day after retinal photocoagulation. Results Three days after photocoagulation, significant elev ated IOP and narrowed chamber angle were observed in control group and 4 eyes (1 1.11%) in Tanakan group (Plt;0.01)． Choroidal detachment in 32 eyes (88.89%) in control group and in 2 eyes (5.56%) in Tanakan group and the severity of ciliochoroidal detachment in tanakan group was significantly lower than that in control group． Conclusion Tanakan is effective to prevent the complications of anterior segment, such as ciliochoroidal detachment, elevation of IOP, narrowing of chamber angle occurring early after retinal photocoagulation and reduce the severity of ciliochoroidal detachment． (Chin J Ocul Fundus Dis, 2001,17:187-189)
Objective To explore the effects of drugs on functions of mitochondria in retinal nerve cells, and to lay a foundation of the investigation of drug protection for retinal nerve cells. Methods Cultivation of the retinal nerve cells of 8 eyes of neonatal calves was performed. The changes of fluorescent density of the mitochondria of cultured cells labeled by dye rhodamine 123 (Rh123) before and after the activation of the medicines, including ferulic acid (FA), arginine, glycine,taurine, vitamine E and brain derived neurotrophic factor( BDNF) respectively, were detected by laser-scanning confocal microscopy. Results FA with the concentration of 500 μg/ml led the diphasic variation of the fluorescent intensity of mitochondria. After scanning for 60.772 seconds when treated with FA firstly, the fluorescent intensity decreased rapidly (from 45.425±4.153 to 22.135±5.293); while after 112.774 seconds when treated secondly, the in tensity increased obviously (from 19.655±4.383 to 28.247±4.764), and after 168.773 seconds when treated thirdly the intensity still increased. After scanning for 56.457 seconds when treated with vitamin E (12.5 mg/ml), the fluorescent in tensity increased obviously (from 88.255±5.039 to 111.273±4.529), which suggested that vitamin E with the concentration of 12.5 mg/ml strengthen the fluorescent intensity. After scanning for 58.147 and 134.148 seconds when treated with BDNF(50 ng/ml) respectively, the fluorescent intensity increased obviously (from 69.115±5.038 to 77.225±5.131) which suggested that BDNF with the concent ration of 50 ng/ml led the increase of the fluorescent intensity. Glycine (2.5 mg/ml) and arginine(30 mg/ml) didn’t affect the fluorescent intensity of mitochondria, and taurine (6.25 mg/ml) caused the appreciable decrease of the fluorescent intensity . Conclusion FA, BDNF and vitamin E may promote the metabolism of retinal nerve cells via the path of mitochondria, while amino acids may adjust the activation of retinal nerve cells through other ways. (Chin J Ocul Fundus Dis，2004，20：229-232)