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目的 :探讨Amadori糖化血清白蛋白对牛视网膜血管二酯酰甘油 (DAG)———蛋白激酶C(PKC)信号级联的影响及d-α-生育酚的干预作用。方法 :体外制备的Amadori糖化的牛血清白蛋白 (AGSA)分别在生理浓度葡萄糖 (5 .5mmol/L)和高浓度葡萄糖 (2 0mmol/L)培养液中作用于新鲜牛视网膜血管。采用薄层层析和放射自显影法测定DAG含量和PKC活性 ;并检测d -α-生育酚预处理后DAG、PKC改变。结果 :在生理葡萄糖浓度下 ,牛视网膜血管暴露于AGSA2 4h或 72h后细胞内DAG含量、PKC活性均较对照组显著增加 ,当AGSA和高葡萄糖同时作用于牛视网膜血管时 ,DAG -PKC级联显著激活 ,分别为正常葡萄糖组的 3.4 7倍和 4 .5 4倍 ;在正常血清培养液中 ,与 5 .5mmol/L的葡萄糖相比 ,2 0mmol/L高糖在 2 4h时并不刺激DAG含量增加 (P >0 .0 5 ) ,而 72h时则较对照组增加 4 5 % ,PKC活性较对照增加 5 6 % ,而d -α -生育酚可逆转上述生化改变。结论 :Amadori糖化血清白蛋白可在生理葡萄糖浓度下刺激DAG -PKC途径活化 ,从而影响血管一系列生理功能 ,而d -α-生育酚对血管生化改变有保护作用。
Objective: To investigate the effect of Amadori glycosylated serum albumin (BSA) on the signaling cascades of bovine retinal blood vessel diglyceride (DAG) --- protein kinase C (PKC) and the intervention of d-α-tocopherol. Methods: Amadori glycosylated bovine serum albumin (AGSA) prepared in vitro was applied to fresh bovine retinal vessels in physiological glucose (5. 5 mmol / L) and high concentration glucose (20 mmol / L) The content of DAG and the activity of PKC were determined by TLC and autoradiography. The changes of DAG and PKC after d-α-tocopherol pretreatment were detected. RESULTS: Under physiologic glucose concentration, intracellular DAG content and PKC activity of bovine retinal blood vessels exposed to AGSA2 for 4h or 72h were significantly increased compared with that of control group. When AGSA and high glucose were simultaneously administered to bovine retinal vessels, DAG-PKC cascade Which were 3.4 7 times and 4.54 times higher than normal glucose group respectively. Compared with 5.5 mmol / L glucose, 20 mmol / L high glucose did not stimulate at 24 hours in normal serum culture medium DAG increased (P> 0.05), while at 72h, it increased by 45% and PKC activity increased by 56%, while d-α-tocopherol reversed the biochemical changes. Conclusions: Amadori glycosylated serum albumin can stimulate the activation of DAG-PKC pathway under physiological glucose concentration and thus affect a series of physiological functions of blood vessels, while d-α-tocopherol has a protective effect on vascular biochemical changes.