ATP sensitive potassium (K(ATP)) channels have important functions in neuroendocrine tissue, in smooth and skeletal muscle and in the heart. In pancreatic beta cells the K(ATP) channels, which are formed by 4 ion channels (Kir6.2) and 4 regulatory sulfonylurea receptors (SUR1), control the glucose stimulated release of insulin. The Kir6.2/SUR1 K(ATP) channels are also present in the brain and in other neuroendocrine tissues[1]. KATP channel subunits expressed in rat liver and the diversity of KATP channel subunit composition might form different types of KATP channels. This is applicable to hepatocytes, HSCs, various types of Kupffer cells and sinusoidal endothelial cells[2]. VU0071063 is a potent and specific Kir6.2/SUR1 opener (EC50=7.44 μM) and can be used for investigating Kir6.2/SUR1 expressed in the pancreas and brain. VU0071063 inhibits insulin secretion by inducing hyperpolarization of β-cell membrane potential[3]. VU0071063 (1 nM~1 mM; HEK-293 cells) dose dependently opens Kir6.2/SUR1. VU0071063 (0~20 μM; isolated cells) inhibits β-Cell excitability in mouse Islets. VU0071063 (10 μM; 1 hour; isolated cells) inhibits glucose-stimulated insulin secretion. VU0071063 dose dependently and reversibly hyperpolarizes the β-cell membrane potential, which, in turn, inhibits glucose-stimulated Ca2+ entry and insulin secretion. The actions of VU0071063 on the β-cell membrane potential are reversed by tolbutamide, and glucose stimulated insulin secretion is unaffected by the inactive analog 34MT, indicating that the effects are mediated through Kir6.2/SUR1. VU0071063 (50 mg/kg; i.p.; 4 hours) leads to a significant increase in blood glucose at 60 minutes[4].
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