KCNJ11-encoded Kir6.2 assembles with ATP-binding cassette sulphonylurea receptors to generate ATP-sensitive K+ (KATP) channel complexes. Expressed in tissues with dynamic metabolic flux, these evolutionarily conserved yet structurally and functionally unique heteromultimers serve as high-fidelity rheostats that adjust membrane potential-dependent cell functions to match energetic demand. Geneti...

There is wide speculation that ATP-sensitive K+(KATP) channels serve a protective function in the mammalian brain, being activated during periods of energy failure. The aim of the present study was to determine if KATP channels also have a protective role in the anoxia-tolerant turtle brain. After ouabain administration, rates of change in extracellular K+ were measured in the telencephalon of ...

Discovered in the cardiac sarcolemma, ATP-sensitive K+(KATP) channels have more recently also been identified within the inner mitochondrial membrane. Yet the consequences of mitochondrial KATP channel activation on mitochondrial function remain partially documented. Therefore, we isolated mitochondria from rat hearts and used K+ channel openers to examine the effect of mitochondrial KATPchanne...

Reproductive hormone secretions are inhibited by fasting and restored by feeding. Metabolic signals mediating these effects include fluctuations in serum glucose, insulin, and leptin. Because KATP channels mediate glucose-sensing and many actions of insulin and leptin in neurons, we assessed their role in suppressing LH secretion during food restriction. Vehicle or a KATP channel blocker, tolbu...

Closure of ATP-sensitive K+ channels (KATP channels) is a key step in glucose-stimulated insulin secretion. The precise mechanism(s) by which glucose metabolism regulates KATP channel activity, however, remains controversial. It is widely believed that the principal determinants are the intracellular concentrations of the metabolic ligands, ATP and ADP, which have opposing actions on KATP chann...

NES2Y is a proliferating human insulin-secreting cell line that we have derived from a patient with persistent hyperinsulinemic hypoglycemia of infancy. This disease is characterized by unregulated insulin release despite profound hypoglycemia. NES2Y cells, like beta-cells isolated from the patient of origin, lack functional ATP-sensitive potassium channels (KATP) and also carry a defect in the...

Huh, Joon, Garrett J. Gross, Hiroshi Nagase, and Bruce T. Liang. Protection of cardiac myocytes via d1-opioid receptors, protein kinase C, and mitochondrial KATP channels. Am J Physiol Heart Circ Physiol 280: H377–H383, 2001.—The objective of the present study was to investigate the role of d1-opioid receptors in mediating cardioprotection in isolated chick cardiac myocytes and to investigate w...

The -cell of the pancreatic islet modulates glucose homeostasis by secreting glucagon that acts primarily by driving hepatic glucose production. Glucose sensing of the -cell becomes defective in both type 1 and type 2 diabetes, resulting in hyperglucagonemia that likely contributes to hyperglycemia (1). Thus, it is important to elucidate the signals that trigger glucagon secretion and the trans...

The ATP-sensitive K+ channels (KATP) are characterized by strong inhibition by intracellular ATP but their activity is also modulated by various intra- and extracellular factors with complicated and undefined mechanism. These factors include a low concentration of ADP (or ATP/ADP ratio), a mildly low pH, G-protein coupled process, adenosine and so on. Intracellular ATP has a ligand action to in...

Substantial evidence has shown that obstructive jaundice can induce vascular hyporesponsiveness. The present study was designed to investigate mechanisms of MaxiK channel and KATP underlying cholestasis-induced vascular dysfunction. The isolated thoracic aorta was used to explore norepinephrine (NE)-induced contraction. The function of MaxiK and KATP channels were investigated using whole-cell ...