AIM To investigate the role of calcitonin gene-related peptide (CGRP) on diabetic cardiovascular complications. METHODS Through the technique of cell culture in vitro and by the methods of MTT colorimetric analysis and flow cytometry to inspect the effect of CGRP(1, 10, 100 nmol*L-1) on the proliferation of vascular smooth muscle cells(VSMC). RESULTS CGRP concentration- and time-dependently inhibited the VSMC proliferation of normal rats and streptozotocin-diabetic rats, moreover, the action was stronger in diabetic VSMC than in normal control. To diabetic rat VSMC, pinacidil (1.0 μmol*L-1), an ATP-sensitive K+ channel (KATP) opener, enhanced the anti-proliferative effect of CGRP(10 nmol*L-1), made the inhibition rates changed from (49.3±1.2)% to (58.3±3.9)%, and glibenclamide (10 μmol*L-1), a KATP channel blocker, partly inhibited the effect of CGRP(10 nmol*L-1), made the inhibition rates changed from (49.3±1.2)% to (35.6±1.1)%. But for normal control VSMC, both pinacidil and glibenclamide had no evident influence on the action of CGRP. On the other hand, in diabetic group, CGRP distinctly increased the cell number in G0/G1 phase, but decreased the number in S and G2/M phase, when CGRP and pinacidil acted together, the number in G0/G1 phase was larger than that acted by CGRP alone. CONCLUSION CGRP has marked anti-proliferatrion effect on diabetic VSMC.%目的研究降钙素基因相关肽(CGRP)对体外培养的糖尿病大鼠血管平滑肌细胞(VSMC)增殖的影响.方法用酶标仪和流式细胞仪检测不同浓度CGRP(1, 10, 100 nmol*L-1)对糖尿病大鼠VSMC的增殖的影响.结果 CGRP呈浓度和时间依赖性的抑制糖尿病大鼠VSMC增殖,格列本脲(1 μmol*L-1)部分阻断CGRP(10 nmol*L-1)对培养的糖尿病组VSMC的抗增殖作用,使其对VSMC的抑制率由(49.3±1.2)%减至(35.6±1.1)%,吡那地尔(1 μmol*L-1)可增强其抗增殖作用,使其对VSMC的抑制率由(49.3±1.2)%增至(58.3±3.9)%.CGRP(10 nmol*L-1)可使停留于G0/G1细胞增多,进入S期和G2/M期的细胞数目减少,吡那地尔(1 μmol*L-1)能增强其作用.结论 CGRP对糖尿病大鼠VSMC具有显著的抗增殖作用,使处于G0/G1期细胞增多,S和G2/M期细胞减少.
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