Author/Editor		Chowdhury, HH; Zorec, R
Title		Adipocyte cell size enlargement involves plasma membrane area increase
Type		članek
Source		Arch Physiol Biochem
Vol. and No.		Letnik 118, št. 3
Publication year		2012
Volume		str. 121-7
Language		eng
Abstract		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.
Descriptors		ADIPOCYTES ANIMALS CELL MEMBRANE CELL SIZE CELLS, CULTURED ENDOCYTOSIS EXOCYTOSIS INSULIN MEMBRANE POTENTIALS PATCH-CLAMP TECHNIQUES RATS RATS, WISTAR