Author/Editor		Chowdhury-Haque, Helena
Title		Vpliv inzulina na dinamiko sprememb površine membrane adipocita podgane v kulturi
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		2002
Volume		str. 51
Language		slo
Abstract		In the last decade it has become clear that adipocytes secrete many different products, which have important physiological role, hence fat tissue is considered as a major endocrine organ in the body. In addition adipocytes are important target cells for hormone action, especially insulin. The aim of our research was to understand the molecular mechanisms of insulin action in single adipocytes. It is well established that insulin induces the translocation of glucose transporter isoform 4 (GLUT4) to the plasma membrane of adipocytes. This in turns triggers an increased permeability of the adipocyte plasma membrane to glucose. The exact mechanism of stimulation of this process is not known, but it is very likely that the exocytosis of the GLUT4 vesicles is involved in the last step of these events. Exocytosis is the universal process of eucarionic cells where the vesicle membrane fuses with the plasma membrane. This event is inseparably bound to the increase of the plasma membrane area. Therefore, if GLUT4 translocation includes exocytosis, one should be able to detect an insulin-induced increase in the surface area of the plasma membrane in a single adipocyte. In this study we wanted to establish whether the resulting effect of insulin-induced signaling pathway is regulated exocytosis of membrane vesicles. To study this process on the single cell, we isolated and cultured rat adipocytes in primary culture. We used electrophysiological method *patch-clamp* to measure membrane capacitance (Cm). Cm is linearly correlated to the membrane surface area, which is changing due to exocytosis and endocytosis. We showed that ATP application resulted in an increase of the Cm, however increase in Cm, after insulin addition was not significantly different from control cells. (Abstract truncated at 2000 characters).
Descriptors		ADIPOCYTES INSULIN EXOCYTOSIS ELECTRIC CONDUCTIVITY BIOLOGICAL TRANSPORT, ACTIVE RATS FLUORESCENT DYES GLUCOSE CELLS, CULTURED