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Objective To observe the effects of Shuangdan Mingmu Capsules on the expressions of HIF-1α and NF-κB; To explore its possible mechanism of treatment. Methods SD rats were injected with STZ (50 mg/kg) into the tail vein to induce diabetes mellitus. After the DR model was confirmed by fundus fluorescein angiography, the rats were randomly divided into model group, Shuangdan Mingmu Capsules group and positive medicine group, and normal rats were set as control group. After the last administration, the blood glucose level and retinopathy in rats were measured. The protein and gene expression of HIF-1α and NF-κB in the retina were detected by Western blot and RT-PCR respectively. Results Compared with control group, the blood glucose in the model group was significantly increased; the retinal capillaries increased; the leakage of fluorescein was obvious; the protein and gene expressions of HIF-1α,NF-κB were significantly increased.After administration of Shuangdan Mingmu Capsules,the model rats decreased blood glucose; retinal microvascular volume decreased; fluorescein leakage area was significantly reduced; protein and gene expressions of HIF-1α and NF-κB were decreased. Conclusion Shuangdan Mingmu Capsules can effectively inhibit the neovascularization of DR rats and protect the retina, which may be related to the down-regulation of the expressions of HIF-1α and NF-κB.
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Abstract?AlM: To observe the effects of Shuangdanmingmu capsule on VEGF expression and retinal vascular morphology in rats with diabetic retinopathy ( DR) .?METHODS: DR rats were fed with Shuangdanmingmu capsule. By comparing with the normal group, the model control group, and positive control group, the effect of Shuangdanmingmu capsule on retinal tissue of DR rats was observed under electron microscopy. After HE staining, retinal structure was observed under the light microscope. lmmunohitochemical staining was used to detect the VEGF expression in retina.?RESULTS:Two months after treatment, the layers tissue of retina presented mild edema, capillary pericytes performed edema, mitochondria showed mild swelling and less clear structure, some endothelial cells showed slight proliferation in Shuangdanmingmu group. Compared with the normal group, the expression level of VEGF in retina increased in the other groups, especially in model control group. A significant differential in expression of VEGF was found between Shuangdanmingmu group, positive control group and model control group (P<0. 01).? CONCLUSlON: Shuangdanmingmu capsule can effectively improve the retinal microvascular, reduce edema and necrosis of each layer of retina, improve the ultrastructure of retina's tissue and inhibit VEGF expression in DR rats.
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<p><b>OBJECTIVE</b>To examine the effects of Pb2+ on N-methyl-D-aspartate (NMDA)-, K(+)- and quisqualate(QA)/kainite(KA)-induced increases in intracellular free calcium concentration ([Ca2+]i) in cultured fetal rat hippocampal neurons in order to explain the cognitive and learning deficits produced by this heavy metal.</p><p><b>METHODS</b>Laser scanning confocal microscopy was used.</p><p><b>RESULTS</b>The results clearly demonstrated that adding Pb2+ before or after NMDA/glycine stimulation selectively inhibited the stimulated increases in [Ca2+]i in a concentration-dependent manner. In contrast, Pb2+ treatment did not markedly affect increases in [Ca2+]i induced by an admixture of QA and KA. The minimal inhibitory effect of Pb2+ occurred at 1 mumol/L, and more than seventy percent abolition of the NMDA-stimulated increase in [Ca2+]i was observed at 100 mumol/L Pb2+. Evaluation of Pb(2+)-induced increase in [Ca2+]i response to elevating extracellular concentrations of NMDA, glycine or calcium revealed that Pb2+ was a noncompetitive antagonist of both NMDA and glycine, and a competitive antagonist of Ca2+ at NMDA receptor channels. In addition, Pb2+ inhibited depolarization-evoked increases in [Ca2+]i mediated by K+ stimulation (30 mumol/L), indicating that Pb2+ also depressed the voltage-dependent calcium channels. Also, the results showed that Pb2+ appeared to be able to elevate the resting levels of [Ca2+]i in cultured neurons, implying a reason for Pb(2+)-enhanced spontaneous release of several neurotransmitters reported in several previous studies.</p><p><b>CONCLUSION</b>Lead can inhibit NMDA-, K(+)-, QA/KA-induced increases in intracellular [Ca2+]i in cultured hippocampal neurons.</p>