Avtor/Urednik		Chowdhury, Helena H; Kreft, Marko; Zorec, Robert
Naslov		Rapid insulin-induced exocytosis in white rat adipocytes
Tip		članek
Vir		Pflugers Arch
Vol. in št.		Letnik 445
Leto izdaje		2002
Obseg		str. 352-6
Jezik		eng
Abstrakt		Insulin is believed to increase glucose permeability of adipocytes by regulating the incorporation of glucose transporters into the plasma membrane by exocytosis. This process involves fusion of membranebound cellular compartments with the plasma membrane, thus influencing the plasma membrane area. However, insulin-induced changes in plasma membrane area have not yet been demonstrated. In the present study we monitored fluorescence intensity with a confocal microscope to study the effect of insulin on adipocyte plasma membrane area. After cell isolation and adhesion to a glass cover-slip, adipocytes were stained with the dye FM 1-43, a membrane area reporter. At rest, the rate of fluorescence intensity increase was initially high, but gradually stabilized at 2%/min. This steady increase in fluorescence is due to a slow rate of exocytosis coupled to endocytosis, since the removal of FM1-43 from the bath did not abolish FM1-43 fluorescence. Insulin addition caused an abrupt increase of fluorescence intensity of 4%/ min, which was significantly higher than in controls. These results suggest rapid, insulin-induced incorporation of new membrane into the plasma membrane by exocytosis.
Deskriptorji		ADIPOCYTES INSULIN EXOCYTOSIS MICROSCOPY, CONFOCAL TIME FACTORS RATS