To test Joossens's hypothesis that salt is a common cause of both cerebrovascular disease (CVD) and stomach cancer (SC), the standardized mortality ratios (SMRs) of SC and CVD were related to urinary Na and K and urinary Na/creatinine (Cr), K/Cr, and Na/K ratios. Fifty spot urine of females between 40 to 69 years was collected from each of 169 municipalities (88 urban and 81 rural) covering all...

Sodium (Na) homeostasis is crucial for life, and Na levels in body fluids are constantly monitored in the brain. The subfornical organ (SFO) is the center of the sensing responsible for the control of salt-intake behavior, where Na(x) channels are expressed in specific glial cells as the Na-level sensor. Here, we show direct interaction between Na(x) channels and alpha subunits of Na(+)/K(+)-AT...

Apart from Na(+),K(+)-ATPase, a second sodium pump, Na(+)-stimulated, K(+)-independent ATPase (Na(+)-ATPase) is expressed in proximal convoluted tubule of the mammalian kidney. The aim of this study was to develop a method of Na(+)-ATPase assay based on the method previously used by us to measure Na(+),K(+)-ATPase activity. The ATPase activity was assayed as the amount of inorganic phosphate li...

BACKGROUND Intracellular sodium concentration ([Na(+)](i)) modulates cardiac contractile and electrical activity through Na/Ca exchange (NCX). Upregulation of NCX in heart failure (HF) may magnify the functional impact of altered [Na(+)](i). METHODS AND RESULTS We measured [Na(+)](i) by using sodium binding benzofuran isophthalate in control and HF rabbit ventricular myocytes (HF induced by a...

Ouabain-resistant Na and Li effluxes in erythrocytes from 18 normal subjects and 19 hypertensive subjects were studied in fresh cells that contained about 9 mmol Li and 2.5 or 6.5 mmol Na per liter of erythrocytes after intact cells had been incubated for 5 hours in 110 mM Li, 40 mM Na medium, with or without ouabain 10(-4) M. Outward Na cotransport was estimated at both internal Na concentrati...

40 41 Na/K pump activity and metabolic rate are both higher at day in the suprachiasmatic nucleus 42 (SCN) that houses the circadian clock. Here we investigated the role of intracellular Na and 43 energy metabolism in regulating Na/K pump activity and neuronal excitability. Removal of 44 extracellular K to block the Na/K pump excited SCN neurons to fire at higher rates and return 45 to normal K...

Whole-cell patch-clamp recordings were performed on acute brain slices of male rats to investigate the ability of the neurons of the median preoptic nucleus (MnPO) to detect fluctuation in extracellular osmolarity and sodium concentration ([Na+]out). Local application of hypotonic and hypertonic artificial CSF hyperpolarized and depolarized the neurons, respectively. Similar responses obtained ...

Two mechanisms of Na+ influx have been observed using synaptosomal plasma membrane vesicles purified by density gradient centrifugation from a synaptosomal hypotonic lysate. First, a 5-fold increase in uptake over basal Na+ entry occurs with 50 microM veratridine. The veratridine-dependent Na+ uptake is partially inhibited by 2 microM tetrodotoxin with an apparent time dependency of action (hal...

The Na+-K+-ATPase, localized in the basolateral membrane of enterocytes plays a major role in nutrient transport in the small intestine by transferring K+ ions into and Na+ out of the cell. Within the enterocyte, homeostasis is maintained by active exclusion of Na from the cell by the Na+,K+-adenosine triphosphatase (ATPase) or sodium pump. Because much of the intestinal nutrient transport is b...