| Part IExpression of RhoA, ROCK-2 and ET-1 and their correlation in rat retina after acute elevated intraocular pressureAim:To investigate the distribution and expression of RhoA, Rho-associated kinase-2 (ROCK-2) and endothelin-1(ET-1) and their correlation in rat retina after acute elevated intraocular pressure (IOP).Methods:30 SD rats were divided into 5 groups at random:N group (normal), H1 group, H3 group, H5 group, and H7 group (1st,3rd,5th,7th day respectively after acute elevated IOP). After operation, immuno-histological assay was carried out on paraffin sections of retina and the distribution and average optical density (OD) of RhoA, ROCK-2 and ET-1 were observed, meanwhile the correlation of ET-1 with RhoA and ROCK-2 was analyzed. The expression of RhoA and ROCK-2 was analyzed by Western blotting analysis.Results:In N group, RhoA, ROCK-2 or ET-lwas only distributed in ganglion cells layer (GCL) and not found in other layers. Its distribution was expanded along with the extension of time after acute elevated IOP (p<0.05). Its OD was higher than N group correspondingly (P<0.05 in H1 and H3 group, P<0.01 in H5 and H7 group). Moreover, there was prominently positive correlation of the expression of ET-1 with RhoA (r=0.58738) or ROCK-2 (r=0.80667). The expression of protein of RhoA or ROCK-2 in HI, H3, H5, H7 groups was obviously increased compared with N group (P<0.05), and it augmented along with the extension of time after acute elevated IOP. Furthermore, there was marked difference between adjacent two groups (P<0.05). Conclusion:RhoA/ROCK-2 passage way was activated by injury of acute elevated IOP, its distribution in retina was expanded and the expression of RhoA, ROCK-2 and ET-1 was enhanced, and there was prominently positive correlation between RhoA or ROCK-2 and ET-1. The activation of RhoA/ROCK-2 passage way plays an important role in rat retinal injury after acute elevated IOP.Partâ…¡Neuroprotective effect of different doses Taurine for retinal ganglion cells in rat acute elevated intraocular pressureAIM:TO investigate the neuroprotective effect of different doses Taurine for retinal ganglion cells in rat acute elevated intraocular pressure (IOP).Methods:30 SD rats were divided into 5 groups at random:N group (normal), M group (model), TL group (model+Taurine, Taurine i.p,5mg/kg q. d. began a week before the model preparation), TM group (model+Taurine, Taurine i. p.15mg/kg q. d. began a week before the model preparation) and TH group (model+Taurine, Taurine i.p.25mg/kg q. d. began a week before the model preparation). At first measuring pattern visual evoked potentials (PVEP) and then enucleating the eyes on the 7th day after model preparation, which was established by increasing IOP to 110mmHg (lasting 60min) through intra-anterior chamber infusion of saline solution, d Retinal thickness was measured to analyze the injury situation of retina. TUNEL was employed to observe apoptosis of RGCs through apoptosis index (AI). The results were analyzed using one-way ANOVA and t-test with SPSS 13.0. Results:In M and TL groups, compared with N group, retinal thicknesses were obviously thinned, latent periods of PVEP were significantly elongated and amplitude periods of PVEP were remarkably decreased (all P<0.01). In TM and TH groups, compared with N group, the above indexes were prominently different (all P<0.05). In TL, TM and TH groups, compared with M group, retinal thicknesses were obviously thickened, RGCs AIs were noteworthily decreased, latent periods of PVEP were significantly shorted and amplitude periods of PVEP were remarkably increased (all P<0.05). Meanwhile, all indexes in TH group were obviously superior to TM and TL groups (all P<0.05).Conclusion:Retinal thickness was thinned, RGCs apoptosis occurred, latent period of PVEP was elongated and amplitude period was decreased after acute elevated IOP. Taurine could reduce the above changes, and the effect was dose dependent. So the best dose was 25mg/kg q.d through intraperitoneal injection.Partâ…¢Neuroprotective effect of Taurine for retinal gang l ion cel Is and its influence on the expression of RhoA, ROCK-2, ET-1 in rat acute elevated intraocular pressureAim:To investigate neuroprotective effect of Taurine for retinal ganglion cells and influence for the expression of RhoA, ROCK-2, ET-1 in rat acute elevated intraocular pressure (IOP).Methods:24 SD rats were divided into 4 groups at random:N group (normal), M group (model), MP group (model+PBS, PBS i.p,25mg/kg q. d. began a week before the model preparation) and T group (model+Taurine, Taurine i. p, 25mg/kg q. d. began a week before the model prepartion). Enuleating the eyes and collecting blood from their hearts on the 7th day after operation which was established by increasing IOP to 110mmHg (lasting 60min) through intra-anterior chamber infusion of saline solution, TUENL was employed to observe apoptosis of RGCs through apoptosis index (AI), immuno-histological assay to carry out on paraffin sections of retina and to research the expression with average optical density (OD) of RhoA, Rho-associated kinase-2 (ROCK-2) and endothelin-1 (ET-1), Western blotting to view the expression of RhoA and ROCK-2, radio-immunity assay to survey the content of ET-1 in blood plasma, and blood rheometer to measure the blood viscosities, blood cell aggregation index (BCAI) and hematocrit (HCT). The results were analyzed using one-way ANOVA and t-test with SPSS 13.0.Results:In M and MP groups, the OD of RhoA (P<0.01), ROCK-2 (P<0.01) and ET-1 (P<0.01) in retina, the expression of RhoA (P<0.01) and ROCK-2 (P<0.01) in retina and the content of ET-1 (P<0.05) in blood plasma, and the blood viscosities (P<0.05), BCAI (P<0.05) and HCT (P<0.05) were all obviously increased compared with N group, but there was no significant difference between them (P>0.05). In T group, the OD of RhoA (P<0.05), ROCK-2 (P<0.05) and ET-1 (P<0.05) in retina, the expression of RhoA (P<0.05) and ROCK-2 (P<0.05) in retina and the content of ET-1 (P<0.05) in blood plasma, and the blood viscosities (P<0.05), BCAI (P<0.05) and HCT (P<0.05), and RGCs AI (P<0.01) were all prominently decreased compared with M or MP groups.Conclusion:Taurine could protect RGCs in rat acute elevated IOP and its mechanism may be related to inhibiting RhoA/ROCK-2 pathway, reducing actin-myosin cross link, restraining smooth muscle contraction, diminishing ET-1, and depressing blood viscosity.
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