Objective To investigate the effects of advanced glycation endproducts (AGEs) on proliferation of pericytes of bovine retinal capillary vessels and expression of transforming growth factor beta;(TGF-beta;). Methods The proliferation of pericytes detected by methyl thiazolyl tetrazolium (MTT) colorimetric assay, cellular cycle of pericytes was analyzed by flow cytometry was used to analyze cell, and TGF-beta; protein expression of pericytes was observed by immunofluorescent staining. Results AGEs inhibited the proliferation of pericytes of bovine retinal capillary vessels, stopped the cellular cycle of pericytes in synthesis phase (S phase), increased the number of apoptotic cells obviously (Plt;0.01), and promoted the expression of TGF-beta; proteinof perycytes. Conclusions AGEs may promote the apoptosis of pericytes by inhibiting the proliferation of pericytes to lead the decrease of pericytes number, and may accelerate diabetic retinopathy by promoting the expression of TGF-beta; protein of pericytes. (Chin J Ocul Fundus Dis, 2006, 22: 20-23)
Objective To investigate the effects of gamma;-interferon (IFN-gamma; on the expression of costimulatory molecules B7-1 (CD80) and B7-2 (CD86) and Fas/FasL in human retina. Methods Nine human eyes were obtained from the eye-bank of Zhongshan Ophthalmic Center. Six eyes were used for making retinal wholemounts, and 12 retinal wholemounts from each eye were put into the 24-hole culture board which had 2ml DMEM/F12 culture medium in each hole. The wholemounts were divided into 3 groups whose concentration of IFN-gamma; was 0, 200, and 1000 U/ml respectively. After cultured in 37℃ culture box (95%O 2，5%CO 2) for 24 hours, the expressions of B7-1 (CD80), B7-2 (CD86), and Fas/FasL on these retinal wholemounts were detected by immunohistochemical method. The retinal wholemounts from 3 healthy people were detected by immunohistochemical method as the control. Results Expression of FasL but not B7-1, B7-2 or Fas was found in the control group, while the expression of B7-1, B7-2 and Fas and increased expression of FasL were found after cultured with IFN-gamma;. Conclusion IFN-gamma; may be involved in the occurrence of ocular immune response and induction of apoptosis via the stimulation of expression of costimulatory molecules and Fas/FasL, which plays an important role in the activation of T lymphocytes. (Chin J Ocul Fundus Dis, 2006, 22: 117-119)
Objective To investigate the effect of tetrandrine (Tet) on experimental choroidal neovascularization and the effect of Tet on retinal structure and function. Methods Choroidal neovascularization was induced in 20 Brown Norway (BN) rats (40 eyes) by diode laser (wavelength: 810 nm; exposal time: 0.1 second; facular diameter:100 mu;m; energy: 120 mW), and the rats were divided randomly into experimental and control group with 10 rats (20 eyes) in each group. In experimental group, 0.05 ml Tet with the concentration of 3.21 mu;mol/L was injected intravitreously 0 and 3 days after laser photocoagulation; in the control group, the rats underwent an intravitreous injection with the same volume of sodium chloride solution. The incidence of CNV was evaluated by fundus fluorescein angiography (FFA) 14 days after laser photocoagulation. Five right eyes of another Five healthy BN rats underwent intravitreous injection with 0.05 ml Tet with the concentration of 3.21 mu;mol/L, and an intravitreous injection with the same volume of sodium chloride solution was performed on the left eyes. Before injection, 1 hour, and 1 day after the first injection, and 1 hour, 1 day, 7 days, 14 days after e second injection the electroretinography (ERG) was performed on these 5 rats; 14 days after the second injection, the retinae were examined by light microscopy and transmission electron microscopy. Results The incidence of CNV was 23.26% in experimental group，which was obviously lower than that in the control group (63.33%) (Plt;0.01). The ratio of amplitude of b wave of ERG in the rats undergone intravitreous injection with 3.21 mg/ml Tet didnprime;t differ much from which before the injection (Pgt;0.05). There were no structural changes of retinal tissues examined by light and electron microscopy. Conclusion Tet may inhibit choroidal neovascularization in rats; there isnprime;t any significant toxic effect of intravitreous injection with Tet on retina at the dosage of 3.21 mu;mol/L. (Chin J Ocul Fundus Dis, 2006, 22: 242-244)
ObjectiveTo investigate the protective effect and mechanism of betaxolol on optic nerves after experimental retinal ischemia-reperfused injury.MethodsRetinal ischemia was induced in SD rats by increasing intraocular pressure through intracameral infusion. Sixty-eight rats were randomly divided into 3 groups: normal control (eight rats), 0.25% betaxolol treatment (thirty rats) and saline control group (thirty rats). The latter two groups were subdivided into group 1 day, 3 and 7 days after reperfusion, respectively, with 10 rats in each group. Betaxolol and normal saline was applied to the right eyes of the rats in the treatment group and to the ones in normal saline control group, respectively. The amplitude of bwave of electron retinograph (ERG) was observed and the histological and ultrastructural changes were detected by light and electron microscopy. The expression of neural nitrogen oxide synthase (nNOS) was detected by immunohistochemistry. The content of malonyldialdehyde (MDA) and the superoxide dismutase (SOD) activity were measured by spectrophotometer.ResultsBegan from the first day after reperfusion, in saline control group, the amplitudes of ERG bwave reduced continuously, the histopathological damages of retina were aggravating, the expression of nNOS increased, MDA level increased and SOD level decreased persistently, which significantly differed from the normal control group （P＜0.01）; in contrast to the saline control group, the amplitudes of bwave of ERG in betaxolol treatment group after reperfusion got right obviously（P＜0.01）, with alleviated histopathological damages, decreased nNOS positive neurons（P＜0.01）, decreased MDA content（P＜0.01）, and increased SOD activity （P＜0.01）, in which no statistical significance of nNOS positive neurons was found between the treatment group and normal control group （P＞0.01）. ConclusionBetaxolol, by reducing intracellular overfreight ofCa2+, inhibiting production of NO and elevating the ability of anti-oxidation in rat retina, can protect retinal neurons from ischemiareperfused injury.(Chin J Ocul Fundus Dis, 2005,21:249-252)
ObjectiveTo investigate the effect of triamcinolone acetonide (TA) with different dosage and excipient on retina.MethodsThirty-two purebred New Zealand white rabbits randomly divided into 4 groups underwent intravitreous injection with TA. Group 1:4 mg TA without excipient; group 2:25 mg TA without excipient; group 3:4 mg TA with excipient; group 4:25 mg TA with excipient. Electroretinography (ERG) was performed on each rabbit before intravitreal injection, 1 week, 1 and 2 months after the injection. All the animals were killed and the eyeballs were extirpated 2 months after the injection, and pathological examinations including light and electron microscopy were performed.ResultsNo significant difference was found in the latent period of ERG at the points of time before and after the injection in all the groups, but the amplitudes of ERG waves was lower in groups containing excipient than that before the treatment (Plt; 0.01). The results of light and electron microscopy showed damages of tissue or structures of retina in various degrees in groups containing excipient.ConclusionIntravitreous injection of TA with the dosage of ≤25 mg without excipient does no harm to the retinal configuration and function, and excipient may lead to the change of retinal configuration and function.(Chin J Ocul Fundus Dis, 2005,21:229-232)
ObjectiveTo evaluate the security of intravitreal injection with ciproflaxacin to retina.MethodsTweenty-four rabbits were randomly divided into 4 groups with 6 rabbits in each group. 0.1 ml ciproflaxacin in doses of 2 500,5 000,and 10 000 μg was intravitreally injected into the rabbits eyes, retrospectively. And 0.1 ml saline solution was injected into the vitreous body of the rats in the control group. Indirect microscope, light microscope and electroretinogram (ERG) were used to observe the changes of ocular fundus.ResultsNormal results of light microscopy and ultrastructure were found in 250 μg and 500 μg groups; irregularly arranged outer and inner nuclear layers, dropsical or even lost ganglion cells, and ultrastructural changes were in 1 000 μg group. There was no apparent difference of ERG′s a and b amplitudes before and after intravitreal injection with ciproflaxacin in each group.ConclusionIntravitreal injection with ciproflaxacin is safe, and 500 μg or less is the secure dosage in rabbits' eyes. (Chin J Ocul Fundus Dis, 2005,21:180-182)
Objective To observe the effects of high concentr at ion glucose on the calcium-activated potassium channel of rabbits′ retinal Müller cells. Methods The rabbits′retinal Müller cells were cultured in vitro under the condition of high concentration glucose, and identified by immunohistochemical staining and transmission electron microscopy. Patch-clamp technique was used to observe the changes of the calcium-activated potassium channel of retinal Müller cells caused by high concentration glucose at different time.Results High concentration glucose could inhibit the calcium-activated potassium channel of cultured retinal Müller cells in a time-dependent manner. Conclusion High concentration glucose may reduce the biological functions of Müller cells by inhibiting calcium-activated potassium channel. (Chin J Ocul Fundus Dis，2003，19：164-167)