For better understanding of pathophysiological processes leading to increased retention of sodium as a consequence of hyperlipidemia, the properties of renal Na,K-ATPase, a key enzyme involved in maintaining sodium homeostasis in the organism, were studied. Enzyme kinetics of renal Na,K-ATPase were used for characterization of ATP- and Na(+)-binding sites after administration of fish oil (FO) (...

The effects of varying the sodium gradient-either by lowering [Na+]o or by increasing [Na+]i on the electromechanical properties of pregnant rat uterine smooth muscle were studied. In normal tissues, complete removal of external sodium ions (choline, Tris or sucrose as substitutes) induced a strong and maintained contraction which was dependent on the presence of extracellular calcium ions, and...

We studied the cellular membrane enzyme responsible for potassium transport in different Thai populations. We measured plasma and intraerythrocytic concentrations of sodium and potassium, activities of erythrocytic membrane Na, K-activated adenosine triphosphatase (Na, K-ATPase), ouabain-insensitive ATPase, total ATPase and the activity ratio of Na, K-ATPase/total ATPase in 25 healthy blood don...

Excessive sodium gain is a major hindrance of sodium profiling hemodialysis (HD) that offsets the benefit in reducing intradialytic hypotension-related discomforts (IHD). Patients who showed frequent IHD (>30% of the sessions; n = 11) were enrolled in a prospective study that consisted of two phases. In the phase 1 study, eight treatment modalities were evaluated: Conventional HD (control), sod...

Mechanisms that contribute to Na+ influx during and immediately after 5 min anoxia were investigated in cultured rat hippocampal neurons loaded with the Na+-sensitive fluorophore sodium-binding benzofuran isophthalate. During anoxia, an influx of Na+ in the face of reduced Na+,K+-ATPase activity caused a rise in [Na+]i. After the return to normoxia, Na+,K+-ATPase activity mediated the recovery ...

Arthropod photoreceptors are polarized cells displaying distinct surface domains. The distribution of the Na,K-ATPase (sodium pump) over these domains was examined in the honeybee photoreceptor using a monoclonal antibody that specifically recognizes the sodium pump alpha-subunit (approximately 100 kDa). We find that the sodium pump is restricted to sites of the nonreceptive photoreceptor surfa...

The in vivo activation and turnover rates of the sodium pump (Na+, K(+)-ATPase) were investigated in the electrocytes of the electric organ of the elasmobranch Narcine brasiliensis. The Narcine electric organ appears to be an excellent model for the study of sodium pump activation in an excitable tissue. The sodium transmembrane gradient and high-energy phosphagens were concurrently measured by...

Tetragonal Na3SbS4 is synthesized as a new sodium superionic conductor. The discovery of Na vacancies experimentally verifies previous theoretical predictions. Na vacancies, distorted cubic sulphur sublattices and large Na atomic displacement parameters lead to the ionic conductivity as high as 3 mS cm-1, a value significantly higher than those of state-of-the-art sodium sulfide electrolytes.

Transmembrane sodium (Na(+)) fluxes and intracellular sodium homeostasis are central players in the physiology of the cardiac myocyte, since they are crucial for both cell excitability and for the regulation of the intracellular calcium concentration. Furthermore, Na(+) fluxes across the membrane of mitochondria affect the concentration of protons and calcium in the matrix, regulating mitochond...

Renal mass and glomerular filtration rate (GFR) were reduced from normal to approximately 15% of normal in two groups of dogs. One group received a constant salt intake (CSI) throughout the study. The second group was subjected to "proportional reduction" of sodium intake (PRS), a dietary regimen which involved the reduction of sodium intake in exact proportion to the decrement in GFR. In the C...