| Purpose:Diabetic retinopathy (DR) is the most common complication caused by diabetes mellitus (DM). In the past, research over the pathogenesis of DM has been focused on changes of the micro-circulation in the retinal. Recently, it's been shown that it might be the damage to retinal ganglion cells (RGCs) oraround the blood vessels instead of those in the retinal. Probably DR happens when the neurotrophic factors are exhausted by DR. My research was designed to assess the damage of the retinal ganglion cells (RGCs) in rats with DM and the genes related to apoptosis and the expression of the neurotrophic factors. My research was meant to investigate the neurologically protective role Ginseng could play against DR and the possible mechanisms and to find a way to prevent and cure DM by Chinese medicine.Methods:30 male SD rats (weight between 140g and 160g) are randomly divided into 3 groups: control group, DM model group and DM-Ginseng group. The rats were injected STZ (65 mg/kg weight) peritoneanouly and those with a blood glucose level higher than or equal to 16.7 mmol/L are DM model rats. Rats in DM-Ginseng group were with Ginseng (1.5g/kg weight) each day. Blood glucose level and body weights were measured regularly. At week 33, blood tests were done with blood from artery. The eyeballs were removed and retinol slides were made. Retinol structure and RGCs super-structure were observed using and electrical microscopy. Apoptosis of RGCs was measured by Tunel assay and apoptotic RGCs were counted. LSAB method was used to measure the expression level of bcl-2, bax and bFGF in RGCs. Immunological histochemistry assay was used for quantitative analysis. SPSS was used for statistical analysis.Results: (1) Weight of rats in DC were markedly lower than NC(P<0.01),but DP's were obviously higher than DC(P<0.05). (2)The whole blood viscosity(44.86±9.15) and plasma viscosity(1.45±0.12) in DC were significantly higher than NC(P<0.05).Compared to DC, the whole blood viscosity(34.8±8.16) decreased and the blood low shearing viscosity of RBC(13.56±1.82) were increased obviously (P< 0.05).There were no significant difference in the plasma viscosity and HCT. (3) All the retinal tissues in NC were clear and regular. RGCs layer was single and regular, the nucleus was clear, the cell organs were abundant and structures of mitochondria and microtubules were clear. In DC, the retinal tissues were indistinct disturbance.The nerve fiber layer was edematous, RGCs were vacuolated, the chromatin of nucleus aggregated marginally decreased and shrinked. Some of RGCs were necrosis, nucleus were dissolved, mitochondria was adematous, cristae and most of the microtubules in nerve fibers disappeared, cell plasma was vacuolated, the apoptotic body could be found. (4)The positive apoptotic retinal cell were only expressed in RGCs and inner nuclear layer. The number of apoptotic RGCs in DC(4.92±0.16) was significantly higher than in NC by TUNEL(P < 0.01). Compared to DC(11.98±1.56), the number of apoptotic RGCs in DP decreased obviously. (5) bFGF, bcl-2 and Bax were expressed in different retinal tissues of rats within all groups by LSAB. The expression level was the strongest in RGCs layer and then was inner nuclear layer. It was the lightest in outer nuclear layer. Those were measured by Tracon Northern TN-8502.The expression level of bFGF, bcl-2 and Bax were enhanced in DC.compared to DC, the expression of bFGF and bcl-2 was enhanced but Bax was decreased in DP. (6) The expression level of bcl-2 and bFGF was correlated negatively with the number of apoptotic RGCs ( r=-0.703/-0.705, P< 0.05 ), while the expression of Bax was positively ( r=0.937, P< 0.01 ).Conclusion: It's been proved that Ginseng can protect RGCs neurologically as an neurotrophic factor. Ginseng can be used to prevent and cure DM at an early stage. (1) The Ginseng have to lower the blood sugar, and maintain the function of the blood sugar stability.(2) The transforming the big rat of ability, improvement DM of RBC Ginseng can lower the whole... |
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