The activation of a wide range of cellular receptors has been detected previously using a novel instrument, the microphysiometer. In this study microphysiometry was used to monitor the basal and cholinergic-stimulated activity of the Na+/K+ adenosine triphosphatase (ATPase) (the Na+/K+ pump) in the human rhabdomyosarcoma cell line TE671. Manipulations of Na+/K+ ATPase activity with ouabain or removal of extracellular K+ revealed that this ion pump was responsible for 8.8 +/- 0.7% of the total cellular energy utilization by those cells as monitored by the production of acid metabolites. Activation of the pump after a period of inhibition transiently increased the acidification rate above baseline, corresponding to increases in intracellular [Na+] ([Na+]i) occurring while the pump was off. The amplitude of this transient was a function of the total [Na+]i excursion in the absence of pump activity, which in turn depended on the duration of pump inhibition and the Na+ influx rate. Manipulations of the mode of energy metabolism in these cells by changes of the carbon substrate and use of metabolic inhibitors revealed that, unlike some other cells studied, the Na+/K+ ATPase in TE671 cells does not depend on any one mode of metabolism for its adenosine triphosphate source. Stimulation of cholinergic receptors in these cells with carbachol activated the Na+/K+ ATPase via an increase in [Na+]i rather than a direct activation of the ATPase.
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http://dx.doi.org/10.1016/S0006-3495(93)81442-5 | DOI Listing |
Front Med (Lausanne)
January 2025
Eye Center of the 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
Purpose: To report a singular case of cataract caused by toad venom inoculation and to scrutinize the pathological mechanisms through proteomic sequencing of the lens specimen.
Methods: A young Chinese male presented with progressively deteriorating vision in his right eye subsequent to a history of toad venom inoculation. He was diagnosed with a toxic cataract, and underwent phacoemulsification cataract surgery.
J Fish Biol
January 2025
Laboratory of Ecophysiology and Molecular Evolution, National Institute for Amazonian Research, Manaus, Brazil.
Optical characterization of dissolved organic carbon (DOC) freshly collected from the circumneutral "white water" of the Rio Solimoes revealed that it had lower aromaticity, lower molecular weight, and a greater autochthonous content than DOC from the acidic "black water" of the Rio Negro. The tambaqui (Colossoma macropomum), a characid member of the Serrasalmidae, is a model neotropical fish that migrates annually between the two rivers. We analysed ionoregulatory responses of the tambaqui over 24 h in ion-poor water at pH 7.
View Article and Find Full Text PDFJ Headache Pain
January 2025
Department of Neurology, University of Utah, 383 Colorow Drive, Salt Lake City, UT, 84108, USA.
A key unanswered question in migraine neurobiology concerns the mechanisms that make the brain of migraineurs susceptible to cortical spreading depression (CSD, a spreading depolarization that underlies migraine aura and may trigger the migraine pain mechanisms). Important insights into this question can be obtained by studying the mechanisms of facilitation of CSD initiation in genetic mouse models of the disease. These models, all generated from families with hereditary migraine, allow the investigation of the functional consequences of disease-causing mutations at the molecular, cellular, synaptic and neural circuit levels.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Guizhou Key Laboratory of New Quality Processing and Storage of Ecological Specialty Food; School of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China.
Traditional dry-curing methods have a long cycle time and low efficiency, resulting in the inconsistent quality of dry-cured ham. By applying electrical stimulation (ES) technology in the dry-curing process, it was found that ES affected mitochondrial apoptosis by modulating the intracellular environment of muscle cells, which, in turn, enhanced the quality of dry-cured pork loin. Specifically, ES accelerated glycogen and ATP depletion, which led to a rapid decline in pH.
View Article and Find Full Text PDFJ Chem Ecol
January 2025
Department of Nematology, University of California Riverside, Riverside, CA, USA.
Plants produce defensive toxins to deter herbivores. In response, some specialized herbivores evolved resistance and even the capacity to sequester toxins, affecting interactions at higher trophic levels. Here, we test the hypothesis that potential natural enemies of specialized herbivores are differentially affected by plant toxins depending on their level of adaptation to the plant-herbivore system.
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