This report demonstrates that mitochondria isolated from thermogenic Arum spadices possess an ATP-sensitive potassium channel--responsible for electrical potential (DeltaPsi) collapse and mitochondrial swelling--whose characteristics are similar to those previously described in pea and wheat mitochondria. In order to study the relationship between this K(ATP)(+) channel and the uncoupled respiration, linked to thermogenesis, K(+) transport activities were compared with those of mitochondria that were isolated from pea stems, soybean suspension cell cultures and Arum tubers. The channel from Arum spadices is highly active and its major features are (i) potassium flux is performed primarily in an inward-rectifying manner; (ii) the influx of K(+) is associated with a matrix volume increase in both energized and non-energized mitochondria; and (iii) its activity depends on the redox state of electron transport chain (ETC) and oxygen availability. In particular, this paper shows that the K(ATP)(+) channel is inwardly activated in parallel with the alternative oxidase (AO). The activation is linked to an ETC-oxidized state and to high oxygen consumption. The putative role of this K(ATP)(+) channel is discussed in relation to flowering of thermogenic Arum spadices.
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http://dx.doi.org/10.1016/j.jplph.2007.10.012 | DOI Listing |
Acta Neuropathol Commun
January 2025
Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Delayed radiation-induced brain injury (RIBI) characterized by progressive cognitive decline significantly impacts patient outcomes after radiotherapy. The activation of NLRP3 inflammasome within microglia after brain radiation is involved in the progression of RIBI by mediating inflammatory responses. We have previously shown that sulfonylurea receptor 1-transient receptor potential M4 (SUR1-TRPM4) mediates microglial NLRP3-related inflammation following global brain ischemia.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Endocrinology Research Center, Moscow 117292, Russia.
Analyzing the genetic architecture of hereditary forms of diabetes in different populations is a critical step toward optimizing diagnostic and preventive algorithms. This requires consideration of regional and population-specific characteristics, including the spectrum and frequency of pathogenic variants in targeted genes. As part of this study, we used a custom-designed NGS panel to screen for mutations in 28 genes associated with the pathogenesis of hereditary diabetes mellitus in 506 unrelated patients from Russia.
View Article and Find Full Text PDFJ Mol Cell Biol
January 2025
Department of Endocrinology, Beijing Diabetes Institute, Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China.
Insulin secretion is mainly regulated by two electrophysiological events, depolarization initiated by the closure of ATP-sensitive K+ (KATP) channels and repolarization mediated by K+ efflux. Quinine, a natural component commonly used for the treatment of malaria, has been reported to directly stimulate insulin release and lead to hypoglycemia in patients during treatment through inhibiting KATP channels. In this study, we verified the insulinotropic effect of quinine on the isolated mouse pancreatic islets.
View Article and Find Full Text PDFJ Physiol Sci
January 2025
Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, 501-1193, Gifu, Japan; Department of Basic Veterinary Science, Laboratory of Physiology, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, 501-1193, Gifu, Japan; Division of Animal Medical Science, Center for One Medicine Innovative Translational Research (COMIT), Gifu University Institute for Advanced Study, 1-1 Yanagido, 501-1193, Gifu, Japan.
Purines such as ATP are regulatory transmitters in motility of the gastrointestinal tract. The aims of this study were to propose functional roles of purinergic regulation of esophageal motility. An isolated segment of the rat esophagus was placed in an organ bath, and mechanical responses were recorded using a force transducer.
View Article and Find Full Text PDFJ Cereb Blood Flow Metab
January 2025
Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, MO, USA.
Regional blood flow within the brain is tightly coupled to regional neuronal activity, a process known as neurovascular coupling (NVC). In this study, we demonstrate the striking role of SUR2- and Kir6.1-dependent ATP-sensitive potassium (K) channels in control of NVC in the sensory cortex of conscious mice, in response to mechanical stimuli.
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