ATP-sensitive potassium (K(ATP)) channels are bifunctional multimers assembled by an ion conductor and a sulfonylurea receptor (SUR) ATPase. Sensitive to ATP/ADP, K(ATP) channels are vital metabolic sensors. However, channel regulation by competitive ATP/ADP binding would require oscillations in intracellular nucleotides incompatible with cell survival. We found that channel behavior is determi...

Importance: Primary open angle glaucoma, an age-related, retinal neurodegenerative disease of unknown etiology, is treated by lowering intraocular pressure, even though elevated pressure present in only about 60% patients. Since we found that tolbutamide, which inhibits the opening ATP-sensitive potassium channels, modulates aqueous dynamics with a significant increase outflow, and since aquapo...

The aim of this study was to investigate the effects of simvastatin on insulin secretion in mouse MIN6 cells and the possible mechanism. MIN6 cells were, respectively, treated with 0  μ M, 2  μ M, 5  μ M, and 10  μ M simvastatin for 48 h. Radio immunoassay was performed to measure the effect of simvastatin on insulin secretion in MIN6 cells. Luciferase method was used to examine the content of ...

background: the mechanisms underlying cerebral hypercapnic vasodilatation are not fully understood.   objective: to investigate the role of nitric oxide (no) and atp-sensitive potassium (k atp ) channels in basal blood flow regulation and hypercapnia-induced vasodilatation in rabbit cerebral blood vessels.   methods: the change in cerebral blood flow was measured by a laser doppler flowmeter in...

An appropriate concentration of DNP (2, 4-dinitrophenol) is capable of inhibiting the ATP energized mitochondrial volume change induced by gramicidin in the presence of the permeant ions potassium and L-malate. The further addition of the non-mercurial thiol reagent, showdomycin reinstates, an effect of gramicidin which is dependent upon potassium ion. Thus the strategically located nucleophili...

Pinacidil belongs to a novel group of compounds that enhance the potassium permeability of vascular smooth muscle. Evidence also exists that this drug enhances the potassium permeability of cardiac tissue. The purpose of the present investigation was to determine if pinacidil alters potassium-channel activity in heart and, if so, which potassium channel is the target. We used the whole-cell arr...

BACKGROUND Although potassium channels are thought to be responsible for the initiation of hypoxic pulmonary vasoconstriction (HPV), their role in the HPV-inhibitory effect of volatile anesthetics is unclear. The current study tested if the HPV-inhibitory effect of isoflurane and sevoflurane can be affected by changing the potassium-channel opening status with specific potassium-channel inhibit...

The mitochondrial ATP-sensitive potassium channel (mK(ATP)) is important in cardioprotection, although the channel remains molecularly undefined. Several studies have demonstrated that mitochondrial complex II inhibitors activate the mK(ATP), suggesting a potential role for complex II in channel composition or regulation. However, these inhibitors activate mK(ATP) at concentrations which do not...

The presence of adenosine triphosphate-regulated potassium channels (K-ATPs) in midbrain dopamine neurons is currently in dispute. This was investigated using whole-cell patch-clamp recordings from dopamine neurons in slices of midbrain from 9-12-d-old rats. Intracellular dialysis with Mg2+ ATP-free solutions resulted in a membrane hyperpolarization (14 +/- 6 mV), or outward current (102 +/- 27...

The Na-K-ATPase is vital for maintenance of lens transparency. Past studies using intact lens suggested the involvement of tyrosine kinases in short-term regulation of Na-K-ATPase. Furthermore, in vitro phosphorylation of a lens epithelial membrane preparation by Src family kinases (SFKs), a family of nonreceptor tyrosine kinases, resulted in modification of Na-K-ATPase activity. Here, the effe...