ABSTRACT
To study the function and mechanism of the NgR-Rhoa- Rock signal pathways which exists in the retinal ganglion cells apoptosis in diabetes mellitus (DM) rats. ● METHODS: Some healthy SD rats were operated by means of single intraperitoneal injection of 1%streptozotocin based on the standard of 50mg/ kg wight, after that the blood sugar value was greater than 16. 7mmol/ L as DM model, then randomly divided into 3 groups, each group was 10 rats. ln addition to take 10 healthy SD rats as control group. Four groups of rats were bilaterally eyeball intravitreal injection in turn with NgR-siRNA virus 10μ L (siRNA group), NgR-siRNA virus diluted 10μ L ( DM group), NgR - siRNA virus - negative -control solution 10μ L (siRNA blank group), NgR- siRNA virus diluted 10μ L ( normal control group ), and fed normally. During that time, some life indexes like blood glucose, body mass, etc. were measured and recorded. After 12wk, the expression of NgR and Rhoa, HE staining, and TUNNEL staining were detected by Western blot analysis. ● RESULTS: Western blot analysis: compared with normal control group, the expression of NgR and Rhoa in DM group and siRNA blank group increased significantly (P 0. 05); compared with DM group and siRNA blank group, the expression of those proteins significantly lowered in siRNA group. HE staining: compared with normal control group, some extent ganglion cells arranged disorder, irregular shape, spacing not consistent were all found in three groups of model rats;compared with DM group and siRNA blank group, there was some improvement in siRNA group of ganglion cells about the order and shape size. TUNEL staining:compared with normal control group, there were retinal ganglion cells apoptosis in all of three groups of model rats. Compared with DM group and siRNA blank group, the number of retinal ganglion cells apoptotic cells was less, and the shape of cells had improved significantly in siRNA group. ●CONCLUSlON: ln the DM phase, the expression of NgR and Rhoa were up - regulation, the condition of diabetic retinal ganglion cell apoptosis was improved after that the NgR-Rhoa-Rock signal pathways had been inhibited.
ABSTRACT
Background Oxidative stress is one of the pathogenesis mechanisms of diabetic complications.Melatonin is the most powerful antioxidant in living organism.Seldom study on the effects of melatonin on diabetic complications is found in China now.Objective This study aimed to detect the expression and alteration of malonadehyde(MDA),glutathione(GSH)and glial fibrillary acidic protein(GFAP)in retina with experimental diabetes and explore the effects of melatonin on retinal oxidative stress in diabetic rats. Methods The animal models of diabetes were established by injection of 2％ streptozocin via caudal vein(STZ,45 mS/kg)in 48 6-week-old clean SD rats.Isometric citric acid buffer solution wag injected in 24 normal.rats as control group.Seven days after injection of STZ,melatonin(10 mg/kg)was injected into the abdominal cavity of 24 diabetic rats in melatonin group dailv,and the equal volume of normal saline was injected in other 24 diabetic rats(model rats)and 24 rats in normal control group.The animals were sacrificed and retinas were obtained in three groups in 4,6 and 8 weeks respectively.Immunohistochemistry and Western blot were used to detect the expression of GFAP in rat retina.The levels of MDA and GSH in retina homogenate were assayed by spectrophotometer.This experiment complied the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results The expression of GSH in model group was lower than that in melatonin group or control group at 4,6 and 8 weeks (all P<0.05).However,no statistically significant difference was seen in the expression level of GSH between melatonin group and normal control group at 4 and 6 weeks(P>0.05),and in the eighth week,expression of GSH in melatonin group was lower than that in control group(P<0.05).The expressions of MDA and GFAP were more prominent in the model group than in melatonin group and control group in 4,6 and 8 weeks(P<0.05),but no significant difference was found between melatonin group and control group at 4 and 6 weeks(P>0.05).The expressions of MDA and GFAP in melatonin group were higher than those in control group at 8 weeks(P<0.05).Conclusion Melatonin plays a powerful effect in protecting the retina from oxidative stress in diabetes retina by downregulating the MDA level,upregulating GSH level and inhibiting GFAP expression.
ABSTRACT
Background The characters of diabetic retinopathy (DR) include capillary occlusion,microcirculation disturbance and retina neovascularization near ischemic areas of the retina.The pathogenic mechanism is still incompletely clear,but the primary mechanism of DR is the change of permeability of retinal blood capillary.Objective The aim of this study was to investigate the effect of lycium bararum polysaccharides (LBP) on the blood glucose,blood fat and permeability of blood-retinal barrier in diabetic rats.Methods Fifty-four clean adult SD rats were randomized into 4 groups.The diabetes mellitus models were created in 36 SD rats by injection of 45 mg/kg streptozotocin(STZ) via caudal vein.The rats with the blood glucose ＞ 16.7 mol/L were defined as the diabetic mellitus in 72 hours after injection.LBP of 200 rmg/( kg · d) was intragastriccally administered in 18 models once a day in LBP group,and equal volume of normal sodium was used at the same way in 18 models in DM group,and 18 normal rats were as normal control group.The rats were killed in 4,8 and 12 weeks respectively for the detect of blood glucose level,triglyceride,total cholesterol.The retina tissue were isolated for the quantification of vascular permeability using Evans blue method.Results The blood glucose level was significantly elevated in the DM group and LBP group compared with normal control group,and that in LBP group was obviously declined in comparison with the DM group with a 57％,40％,36％ fall off in 4,8,12 weeks respectively,showing a statistically significant differences( P＜0.05 ).The triglyceride concentration was considerably raised in the DM group compared with normal control group in all of the time points( P＜0.01 ),however,the rise of triglyceride concentration was found only in 12 weeks in LBP group(P＜0.05).The cholesterol level was increased in 8 and 12 weeks in DM group compared with normal control group and that of LBP group went up only in 12 weeks (P＜0.0l ).The Evans blue contents in dry retina tissue were(26.23±2.00),(29.78± 1.78 ) and( 34.08±3.03 ) μg/g in 4,8,12 weeks in the DM group,and those of LBP were ( 13.27 ±0.77 ),( 18.01 ± 1.77 ),( 25.05 ±:1.50 ) μg/g,showing statistical differences between two groups ( P＜0.01 ).However,in comparison with normal control group ( 12.34 ±4.30,12.76 ± 2.11,12.45 ±4.40 μg/g),the Even blue content were elevated in various time points (P＜0.01 ).Conclusions LBP can suppress the increase of the blood-retinal barrier permeability in STZ-induced diabetic rat by lowing the levels of blood glucose,triglyceride and total cholesterol.These results suggest that LBP has a therapeutical effect on DR.
ABSTRACT
Patients with epilepsy commonly have language deficits. This study investigates whether language fMRI activation and language dysfunction are systematically related in patients with left medial temporal lobe epilepsy [left-mTLE]. We studied sixteen patients with left-mTLE and 16 healthy controls. Semantic judgment task functional MRI scanning and neuropsychological tests were performed. Activation maps of language function MRI analyzed by analysis of functional neuroimages [AFNI]. There was no difference in activation maps of the semantic judgment task fMRI between left-mTLE and healthy controls group. Compared with a healthy control group, in the left-mTLE group, there was significantly less activation volume in the left language regions of the inferior frontal and Superior temporal gyrus; the left-mTLE group also had significantly lower neuropsychological language scores. Language dysfunction in left-mTLE patients is associated with decline of language fMRI activation