Objective To analyze the protective effects of heat-shock response on the retinae of the rats after retinal ischemic reperfusion injury.Method Twenty Wistar rats (20 eyes) were divided into 4 groups: intracameral perfusion group (group P), intracameral perfusion after quercetin injection group (group P+Q), intracameral perfusion after heat shock group (group P+H), and in tracameral perfusion after quercetin injection and heat shock group (group P+Q+H ). According to the standard program established by International Society for Clinical Visual Electrophysiology, we recorded the results of the dark-adapted electroretinogram (D-ERG ),oscillatory potentials (OPs),and light-adapted ERG (L-ERG) of the rats with intraocular hypertension after induced by heat shock response. The expressions of HSP 70 of the rats in all groups were observed by Western blotting.Results The expression of HSP 70 of the rats in group P+H was the highest in all groups, but the expressions of HSP70 in group P+Q and P+Q+H were inhibited significantly. The amplitudes of a and b wave of ERG and O2 wave of OPs decreased, and the delitescence of them were delayed significantly in rats after intracameral perfusion. The amplitude of b wave of D-ERG and O2 wave of OPs in group P+H were higher than which in group P. Zero hour after perfusion, the amplitudes of all waves in group P+H increased significantly (Plt;0.05). Twenty-four hours after perfusion, the retinal functional resumption of the rats in group P+H was better than which in group P. In group P+Q and P+Q+H, the delitescences of all waves of ERG and O2 wave of OPs were the longest and the amplitudes were the lowest, and some waves even disappeared.Conclusions The heat-shock response may improve the recovery ability of the retinal cells after injury of ischemic reperfusion.(Chin J Ocul Fundus Dis，2003，19：117-120)
In this paper,the changes of activities of enzymes relating toenergy metabolism in rabbit's retina during acute ocular hypertension were observed.The activities of succinate dehydrogenase and adenosine triphosphatase were foud to be reduced,while the activities of the lactatic dehydrognease and glucose-6-phosphatase increased.The results reveal the disturbance of metabolism of energy in retina undergone acute ocular hypertension,and suggest that this might be the underlying factors relating to the defects of the functions and structures of the retina. （Chin J Ocul Fundus Dis,1993,9:141-144）
ObjectiveTo investigate the effect of erigeron breviscapus (EBHM) on ocular hypertension and the protective effect of retinal ganglion cells (RGCs) in rats by regulating mitogen activated protein kinase (MAPK) signaling pathway.MethodsSixty male Sprague-Dawley rats were divided into control group, model group, low-dose EBHM group (group A), medium-dose EBHM group (group B), and high-dose EBHM group (group C) by random number table method. There were 12 rats in the group, the left eye was used as the experimental eye. The rats of model group, group A, group B, and group C were infused with normal saline through the anterior chamber to construct an acute ocular hypertension model; the control group was given general anesthesia only. Then, 2-30 days after modeling, rats in the control group and model group were given 3 ml of normal saline once a day; rats in group A, group B, and group C were given 0.30, 0.45, and 0.60 g/100 g EBHM by intragastric administration, respectively, 1 time/d. The rat intraocular pressure was measured before modeling and 1, 14, and 30 days after modeling, and the proportion of high intraocular pressure model was measured. Thirty days after modeling, hematoxylin-eosin (HE) staining was used to observe the pathological changes of retinal tissue; immunofluorescence staining was used to detect the changes in the number of RGCs; real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was used to detect p38 in the retinas of rats in each group. The relative expression of MAPK and Caspase-3 mRNA; western blot was used to detect p38MAPK and phosphorylation in the retina of rats in each group relative expression of phosphorylate-p38MAPK (p-p38MAPK) and Caspase-3 protein. One-way analysis of variance was used for multi-sample comparison, and SNK-q test was used for comparison between two samples.ResultsOne day after modeling, none of the rats in the control group developed acute ocular hypertension, and the other groups were successfully modeled. Compared with the model group, the rates of acute ocular hypertension at 14 days after modeling in groups B and C were lower (χ2=98.701, P＜0.05), and the rates of acute ocular hypertension at 30 days after modeling in groups A, B, and C were 0. There was no statistically significant difference in the rates of acute ocular hypertension between 14 and 30 days after modeling in the A, B, and C groups (P＞0.05). The results of HE staining showed that the structure of the retina in the control group was complete, and the layers were clearly visible; the RGCs count was not abnormal, and the morphology was plump and round. The retina of rats in the model group became thinner; the number of RGCs was greatly reduced, the morphology was vacuolated, and the arrangement was sparse. The retina of rats in groups A, B, and C became thicker, and the number of RGCs increased, and the retina structure in group C was better restored. The results of immunofluorescence staining showed that the RGCs counts of rats in groups A, B, and C were higher than those in the model group, and the difference was statistically significant (F=297.514, P＜0.05); pairwise comparison between groups, group A was lower than that of group B and C Group (q=2.842, 5.263), group B was lower than group C (q=2.457), the difference was statistically significant (P＜0.05). The results of RT-qPCR and Western blot showed that compared with the model group, the relative expression of Caspase-3 mRNA (F=267.912) and protein (F=692.279) and the relative expression of p-p38MAPK protein in the retina of rats in groups A, B and C. The expression level (F=150.061) all decreased, and the difference was statistically significant (P＜0.05); pairwise comparisons between groups showed that Caspase-3 mRNA (q=6.977, 15.642) and protein (q=6.997, 15.642) relative expression levels and p-p38MAPK protein (q=12.443, 24.358) relative expression levels are lower than groups A and B, group B was lower than group A (q=11.678, 12.471, 10.204), the difference was statistical academic significance (P＜0.05).ConclusionsEBHM can significantly reduce intraocular pressure in rats with acute ocular hypertension, increase RGCs counts, and reduce retinal damage. Its regulatory mechanism may be related to the MAPK pathway.
At present, there are few in vivo experimental studies on anterior chamber flow field, and the relevant technologies are not mature. This study explores the experimental method and key techniques of particle image velocimetry (PIV) for the in vivo measurement of anterior chamber flow field with slow flow velocity in the rabbit with acute intraocular hypertension. The experimental process can be divided into three parts: model construction of rabbit eye with acute intraocular hypertension, in vivo eyeball preparation, and PIV setup. The following key techniques were mainly investigated: the optimal injection strategy of fluorescent particles and the correction strategy for image acquisition errors caused by the effects of image refraction and respiration. The results showed that the best injection method was that 15 μL of fluorescent particles solution was slowly injected into the anterior chamber through the lower part of iris and then the rabbit was released and waited for 13 h. In this way particles were completely distributed in the anterior chamber with the help of the aqueous humor circulation, and then in vivo PIV experiment could be performed. The eyeball should be covered with a square flume filled with ultrasonic coupling gel for the sake of imaging during the experiment. The Maximal Information Coefficient algorithm could be applied to correct the measured results before post-processing calculation. The results indicated that feasible injection strategy of fluorescent particles and the correction strategy for image acquisition are critical to obtain nice experiment effects for the in vivo PIV measurement of anterior chamber flow field in the rabbit with acute intraocular hypertension.
Objective To observe the effects of minocycline to the viability and apoptosis of ratprime;s retinal neuron cells (RNC) under pressure, and to investigate the neuroprotective mechanisms of minocycline against the RNC damage. Methods Establish a model of ratprime;s RNs under pressure cultured in vitro, the protective effect of minocycline is observed by different methods, including observing the morphology of the cells, evaluating the cellsprime; viability by methyl thiazolyl tetrazolium (MTT) colorimetry assay, and detecting the cellular apoptosis with acridine orange/ethidium bromide (AO/EB) double staining by fluorescence microscopy. Immunocytochemistry was used to detect the expression of iNOS and caspase-3 in the cells. Results Obvious morphology changes of RNC were found in cells under pressure compared with the control; the viability of RNC decreased and cellular apoptosis was found in 53.93% cells. The cellular morphology improved in the cells treated by 20 mu;mol/L minocycline, the cellular viability significantly increased, and the cellular apoptosis was found in 17.29% cells. In addition, the expression of iNOS and caspase3 in the treated cells decreased compared with which in the pressured group. Conclusion Minocycline with a certain concentration can effectively inhibit pressureinduced damage and apoptosis of RNC of rats, and the inhibitory effect on expression of iNOS and capases-3 may be the underlying mechanism.