Adipocyte cell size enlargement involves plasma membrane area increase
Adipocyte cell size enlargement involves plasma membrane area increase
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DOI：
10.3109/13813455.2012.677453
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发表时间：
2012-07-01
影响因子：
3
通讯作者：
Zorec, R.
中科院分区：
文献类型：
--
作者：
Chowdhury, H. H.;Zorec, R.
脂肪细胞增大与细胞质脂质含量增加有关，但质膜面积如何随细胞质脂质含量增加而增加尚不清楚。我们监测了单细胞膜表面积的波动，这反映了胞吐和胞吞的动态。我们采用膜片钳技术来测量膜电容（Cm），一个与质膜面积线性相关的参数。具体而言，我们研究了胰岛素是否影响脂肪细胞膜面积动力学。5分钟的细胞暴露于胰岛素使静息C-m增加12 +/- 4%;在对照组中，C-m的变化与零没有区别。我们在显微镜下测量了分离的大鼠脂肪细胞的细胞直径。细胞暴露于胰岛素24小时导致细胞直径显著增加5.1 +/-0.6%。我们得出结论，胰岛素诱导膜面积增加，这可能在慢性高胰岛素血症中促进质膜面积的扩大，与其他胰岛素介导的对脂肪细胞的代谢作用一致。
The adipocyte enlargement is associated with an increase in the cytoplasmic lipid content, but how the plasma membrane area follows this increase is poorly understood. We monitored single-cell membrane surface area fluctuations, which mirror the dynamics of exocytosis and endocytosis. We employed the patch-clamp technique to measure membrane capacitance (C-m), a parameter linearly related to the plasma membrane area. Specifically, we studied whether insulin affects membrane area dynamics in adipocytes. A five-minute cell exposure to insulin increased resting C-m by 12 +/- 4%; in controls the change in C-m was not different from zero. We measured cell diameter of isolated rat adipocytes microscopically. Twenty-four hour exposure of cells to insulin resulted in a significant increase in cell diameter by 5.1 +/- 0.6%. We conclude that insulin induces membrane area increase, which may in chronic hyperinsulinemia promote the enlargement of plasma membrane area, acting in concert with other insulin-mediated metabolic effects on adipocytes.