Department of Pediatrics, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
Mol Cell Biochem. 2011 Mar;349(1-2):77-82. doi: 10.1007/s11010-010-0662-8. Epub 2010 Dec 14.
Altered cellular mitochondrial membrane potential (MMP) has been implicated in the increased insulin resistance and the risk for diabetes. Hyperketonemia is increasingly being identified in type 2 diabetic patients in addition to those with type 1 diabetes. No previous study has examined the effect of hyperketonemia and trivalent chromium on cellular mitochondrial membrane potential (MMP) in any cell type. Using a U937 monocyte cell culture model, this study examined the hypothesis that hyperketonemia decreases and trivalent chromium normalizes the cellular MMP level. Cells were cultured with control and ketone bodies [acetoacetate (AA), β-hydroxybutyrate (BHB)] in the absence or the presence (0.5-100 μM) of Cr(3+) at 37°C for 24 h. The MMP was determined using DiOC6 and flow cytometry. The results show a significant decrease in MMP in cells treated with AA, but not in the cells treated with BHB. The effect of AA on cellular MMP was prevented in chromium (III)-pretreated cells. Thus, hyperketonemia decreases the MMP, and supplementation with chromium (III) normalizes altered MMP, which may play a role in the improvement in glucose metabolism seen after chromium (III) supplementation in some studies with diabetic animals and patients.
细胞线粒体膜电位 (MMP) 的改变与胰岛素抵抗和糖尿病风险增加有关。除了 1 型糖尿病患者外，2 型糖尿病患者的高酮血症也越来越多地被发现。以前没有研究检查过高酮血症和三价铬对任何细胞类型的细胞线粒体膜电位 (MMP) 的影响。本研究使用 U937 单核细胞培养模型，检验了以下假设：高酮血症降低细胞 MMP 水平，三价铬使 MMP 水平正常化。将细胞在 37°C 下用对照和酮体[乙酰乙酸盐 (AA)、β-羟丁酸酯 (BHB)]培养 24 小时，有无 (0.5-100 μM) 铬 (III)。使用 DiOC6 和流式细胞术测定 MMP。结果显示，用 AA 处理的细胞 MMP 显著降低，但用 BHB 处理的细胞 MMP 没有降低。用铬 (III) 预处理的细胞可预防 AA 对细胞 MMP 的影响。因此，高酮血症降低了 MMP，补充铬 (III) 使改变的 MMP 正常化，这可能在一些糖尿病动物和患者的研究中，补充铬 (III) 后改善葡萄糖代谢中发挥作用。
