Author/Editor		Speier, S; Yang, S-B; Sroka, K; Rose, T; Rupnik, M
Title		KATP-channels in beta-cells in tissue slices are directly modulated by millimolar ATP
Type		članek
Source		Mol Cell Endocrinol
Vol. and No.		Letnik 230
Publication year		2005
Volume		str. 51-8
Language		eng
Abstract		In pancreatie beta-cells, inhibition of KATP-channels plays a pivotal role in signal transduction of glucose-induced insulin release. However, the extreme sensitivity of KATP-channels to its ligand ATP as found in inside-out patches is not directly compatible with modulation of these channels at physiological (ATP);. We studied KATP-channel sensitivity to ATP in beta-cells in dispersed culture and in fresh pancreatic tissue slices. Physiological (ATP); blocks more than 99% of KATP-channels in cultured beta-cells, while only 90% in beta-cells in slices, indicating reduced sensitivity to ATP in the fresh slices. Applying cytosolic factors like ADP, phosphatidylinositol-4,5-bisphosphate (PIP2) or oleoyl-CoA did not restore the KATP-channel sensitivity in cultured beta-cells. Our data suggest that interaction between SUR 1 and Kir6.2 subunit of the KATP-channel could be a factor in sensitivity modulation. Tissue slices are the first beta-cell preparation to study direct KATP-channel modulation by physiological (ATP)i.
Descriptors		ISLETS OF LANGERHANS INSULIN ADENOSINE TRIPHOSPHATE POTASSIUM CHANNELS CYTOSOL ADENOSINE DIPHOSPHATE PHOSPHATIDYLINOSITOL 4,5-DIPHOSPHATE COENZYME A PATCH-CLAMP TECHNIQUES MICE, INBRED STRAINS