K+ ATPase Activity (k+ + atpase_activity)

Distribution by Scientific Domains

Selected Abstracts

The effect of desferrioxamine on peroxynitrite-induced oxidative damage in erythrocytes

Aytu Ertabak
Abstract The aim of this study was to investigate the effect of desferrioxamine on peroxynitrite-mediated damage in erythrocytes by measuring the 3-nitrotyrosine level and glutathione peroxidase and Na+ -K+ ATPase activities in vitro. 3-Nitrotyrosine levels were determined by HPLC; glutathione peroxidase and Na+ -K+ ATPase activities were measured by spectrophotometry. Peroxynitrite increased the 3-nitrotyrosine level but decreased both enzyme activities. In the presence of desferrioxamine, glutathione peroxidase activity was increased with a decrease in the 3-nitrotyrosine level. Desferrioxamine was found to possess an important antioxidant activity as assessed in an in vitro system, reducing protein nitration, restorating enzyme activities and maintaining erythrocyte membrane integrity. Copyright 2004 John Wiley & Sons, Ltd. [source]

Detection of endogenous lithium in neuropsychiatric disorders,a model for biological transmutation

Ravi Kumar Kurup
Abstract The human hypothalmus produces an endogenous membrane Na+ -K+ ATPase inhibitor, digoxin. A digoxin induced model of cellular/neuronal quantal state and perception has been described by the authors. Biological transmutation has been described in microbial systems in the quantal state. The study focuses on the plasma levels of digoxin, RBC membrane Na+ -K+ ATPase activity, plasma levels of magnesium and lithium in neuropsychiatric and systemic disorders. Inhibition of RBC membrane Na+ -K+ ATPase activity was observed in most cases along with an increase in the levels of serum digoxin and lithium and a decrease in the level of serum Mg++. The generation of endogenous lithium would obviously occur due to biological transmutation from magnesium. Digoxin and lithium together can produce added membrane Na+ -K+ ATPase inhibition. The role of membrane Na+ -K+ ATPase inhibition in the pathogenesis of neuropsychiatric and systemic disorders is discussed. The inhibition of membrane Na+ -K+ ATPase can contribute to an increase in intracellular calcium and a decrease in magnesium, which can result in a defective neurotransmitter transport mechanism, mitochondrial dysfunction and apoptosis, defective golgi body function and protein processing dysfunction, immune dysfunction and oncogenesis. Copyright 2002 John Wiley & Sons, Ltd. [source]

Contrasts in the hypo-osmoregulatory abilities of a freshwater and an anadromous population of inconnu

K. L. Howland
Juvenile freshwater and anadromous inconnu Stenodus leucichthys regulated plasma ions following a direct transfer from fresh to brackish water (10,15,), but suffered osmoregulatory collapse with 100% mortality in 48 h when directly transferred to 25, salinity. Acclimation to brackish water for 2 weeks improved hypo-osmoregulatory capacity in both populations, with acclimated fish showing smaller increases in blood plasma ion concentrations, higher Na+ -K+ ATPase activity, and lower mortality than non-acclimated fish following transfer to 25, sea water. Anadromous inconnu maintained pre-treatment plasma ion levels during acclimation, whereas these levels increased during acclimation in freshwater inconnu. Juvenile anadromous inconnu are therefore able to adapt physiologically to sea water of at least 25,, if brackish-water acclimation is available, but freshwater inconnu have diminished saltwater tolerance, relative to the anadromous form. [source]

Isoprenoid pathway dysfunction in chronic fatigue syndrome

Ravi Kumar Kurup
Background and aims:, The isoprenoid pathway was assessed in 15 patients with chronic fatigue syndrome (CFS). The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance has any correlation with these disease states. Methods:, The isoprenoid metabolites , digoxin, dolichol and ubiquinone , RBC membrane Na+ -K+ ATPase activity, serum magnesium and tyrosine/tryptophan catabolic patterns were assessed. The free radical metabolism, glycoconjugate metabolism and RBC membrane composition were also assessed. Results:, Membrane Na+ -K+ ATPase activity and serum magnesium levels were decreased while HMG-CoA reductase activity and serum digoxin levels were increased in CFS. There were increased levels of tryptophan catabolites , nicotine, strychnine, quinolinic acid and serotonin , and decreased levels of tyrosine catabolites ,dopamine, norepinephrine and morphine , in CFS. There was an increase in dolichol levels, carbohydrate residues of glycoproteins, glycolipids, total/individual glycosaminoglycans (GAG) fractions and lysosomal enzymes in CFS. Reduced levels of ubiquinone, reduced glutathione and free radical scavenging enzymes as well as increased lipid peroxidation products and nitric oxide were noticed in CFS. The biochemical patterns in CFS correlated with those obtained in right hemispheric dominance. Conclusions:, The role of hypothalamic digoxin and neurotransmitter-induced immune activation, altered glycoconjugate metabolism and resultant defective viral antigen presentation, NMDA excitotoxicity and cognitive and mitochondrial dysfunction in the pathogenesis of CFS is stressed. CFS occurs in individuals with right hemispheric dominance. [source]