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Renal Disease; Fluid and Electrolyte Disorders
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
Unlike many ions and molecules, water cannot be pumped directly in the body. Instead, water moves between sites by osmosis if there is an osmotic gradient and if the barrier separating the two sites contains pores or channels through which it can pass. Aquaporin molecules form water channels in most cell membranes. Intra- and extracellular fluid compartments are normally in approximate osmotic equilibrium. The Na+/K+ATPase pumps sodium out of cells and potassium into cells so: Intracellular fluid has high potassium and low sodium concentrations.Extracellular fluid has low potassium and high sodium concentrations.
The Electrical Properties of Cells
Published in Richard C. Niemtzow, Transmembrane Potentials and Characteristics of Immune and Tumor Cell, 2020
One of the proteins in the membrane of animal cells is the (Na,K)-ATPase. This protein translocates Na+ ions from the intracellular surface of the membrane to the exterior surface, at the same time moving K+ ions from exterior to interior.3 This process requires the utilization of one ATP molecule per translocation. The protein has such a large affinity for intracellular Na+ that, under normal conditions, for every Na+ ion which leaks into the cell from the outside, one Na+ is moved by the ATPase outward. The net effect of this activity is to keep the intracellular Na+ concentration very low and to make the net movement of Na+ across the membrane zero; i.e., Na+appears to be impermeable and can counterbalance the effect of the impermeant intracellular anions.
Cardiac Subcellular Function During Diabetes
Published in Grant N. Pierce, Robert E. Beamish, Naranjan S. Dhalla, Heart Dysfunction in Diabetes, 2019
Grant N. Pierce, Robert E. Beamish, Naranjan S. Dhalla
The mechanisms responsible for these enzymatic alterations in the sarcolemma have been investigated. Insulin treatment of diabetic rats was capable of normalizing Na+,K+-ATPase activity66 which would suggest that those defects are closely related with the disease state. Abnormalities in lipid composition in the heart may also represent important modulatory factors on sarcolemmal enzyme activity. Cholesterol and long-chain acyl-carnitine moieties are likely to be fatty compounds which could potentially cause a depression in sarcolemmal enzyme activity, particularly Na+,K+-ATPase activity.66,67
Role of cinnamon oil against acetaminophen overdose induced neurological aberrations through brain stress and cytokine upregulation in rat brain
Published in Drug and Chemical Toxicology, 2022
Mohammad Ashafaq, Sohail Hussain, Saeed Alshahrani, Osama Madkhali, Rahimullah Siddiqui, Gulrana Khuwaja, M. Intakhab Alam, Fakhrul Islam
Furthermore, oxidative stress in the brain impairs several neurotoxicity biomarkers. APAP induced remarkable changes in the activity of Na+/K+-ATPase, AchE and MAO in similarity with control. Na+/K+-ATPase, AchE, and MAO are exclusive enzymes identified as a therapeutic intervention in neurotoxicity conditions (Abdel-Wahab and Moussa 2019). Na+/K+-ATPase is essential to maintain neuronal function across the neuronal membrane. APAP toxicity decreases the activity of Na+/K+-ATPase in brain tissue and consequently loss in neuronal function. MAO is involved in the catalytic oxidation of amine and an extreme rise in its activity may damage neuronal function. Oxidative stress causes membranous damage which leads to an elevation in AchE activity (Kaizer et al.2005). Significantly, overdose of APAP lessen the cholinergic neurotransmission adequacy by diminishing the degree of acetylcholine in the synaptic cleft and increased activity of AchE. Increased AchE activity further increases oxidative stress perturbation in the brain (Essawy et al.2017). CO treatment significantly attenuated activity of Na+/K+-ATPase, AchE, and MAO in APAP + CO group when compared with APAP.
Topical Administration of ACE Inhibitor Interrupts the Progression of Cataract in Two Kidney One Clip Induced Hypertensive Cataract Model
Published in Current Eye Research, 2022
Jaya Shree, Amrita Singh, Rajesh Choudhary, Devi Prasad Pandey, Surendra H. Bodakhe
Lenticular ions (Na+, Ca2+ and K+) play an important role in maintaining the lens transparency, accumulation of lenticular Na+, Ca2+and reduction in K+ ions increases the cataractogenesis by increasing osmotic stress as suggested by many studies which is also corroborated in our study.43 The level of lenticular ionic content is maintained by Na+K+ATPase and Ca2+ATPase pump activity.44,45 Loss of ATPase pump activity causes accumulation of Na+, Ca2+and decrease in K+ level that led to Ca2+dependent protein proteolysis and ultimately the cataract formation.46 Hypertensive control group showed decrease in Na+K+ATPase and Ca2+ATPase pump activity. The results confirmed that chronic treatment with enalapril (oral) restored the ionic levels by maintaining the ATPase pump activity as compared to hypertensive control group. The results also propose that uncontrolled hypertension is strongly associated with cataract formation which was mitigated by oral treatment with enalapril. Topical administration with enalapril also maintained the ATPase activity and restored the ionic content, which suggest that systemic hypertension has an indirect effect on cataract formation by modulating the ocular RAS.
The effects of titanium nanoparticles on enzymatic and non-enzymatic biomarkers in female Wistar rats
Published in Drug and Chemical Toxicology, 2022
Esin Gülnaz Canli, Cebrail Gumus, Mustafa Canli, Hasan Basri Ila
Na,K-ATPase is a membrane-bound enzyme that transports Na and K ions across the biological membranes in vertebrates, transporting 3 Na ions out of the cell and 2 K ions into the cell. Mg-ATPase is found in the cytoplasm and in the mitochondria and regulates the Mg ion concentration in the cell and used in oxidative phosphorylation in the mitochondria. Both Na,K-ATPase, and Mg-ATPase use requires too much ATP energy to carry out their duties (Howarth et al.2012). They were also shown to be sensitive to environmental pollutants (Guo et al.2013, Singh et al.2013, Canli and Canli 2017, 2019). Studies carried out with mammals showed that oral administration of NPs was found to cause alterations in ATPase activities (Canli et al.2017, 2019a). AChE is an important component of the nerve system, functioning in impulse signaling. It's basic duty is to break down the neurotransmitter called acetylcholine into acetate and choline. Environmental xenobiotic substances including NPs were found to alter the activity of AChE which leads it to be used as a diagnostic tool to detect the effects of xenobiotic in animals (Durmaz et al.2006, Piner and Uner 2012, Silva-Herdade and Saldanha 2013, Yilmaz et al.2015, 2017). Our previous study also showed that aluminum NPs administered orally caused significant decreases in AChE activity in the brain of rats (Canli et al.2019a).