Fish otoliths provide a record of age, growth, and environmental influences. In both trout and turbot, spatial chemical investigation of the endolymph surrounding the otolith (sagitta) showed a lack of uniformity. Proteins, [Formula: see text], and Mg2+ were significantly more concentrated in the proximal (facing the macula) than distal zone, whereas the opposite was observed for K+ and total C...

Ouabain and other cardiotonic steroids (CTS) inhibit Na(+) pumps and are widely believed to exert their cardiovascular effects by raising the cytosolic Na(+) concentration ([Na(+)](cyt)) and Ca(2+). This view has not been rigorously reexamined despite evidence that low-dose CTS may act without elevating [Na(+)](cyt); also, it does not explain the presence of multiple, functionally distinct isof...

To provide novel information on psittacine diets, we analyzed the texture, crude protein, crude fat, Ca, P (total), Mg, K, Na, S, Cu, Fe, and Zn concentrations of crop contents from 10 free-living scarlet macaw (Ara macao) chicks from lowland forests of southeastern Peru. We compared our results with nutrient concentrations of known wild parrot foods and published psittacine dietary recommendat...

Neuropeptide Y (NPY) co-exists with norepinephrine (NE) in sympathetic terminals, and is the most abundant neuropeptide in myocardium. Many studies have focused on the effects of NE on ion channels in cardiac myocytes and its physiological significance has been elucidated relatively profoundly. There have been few investigations, however, on the physiological significance of NPY in myocardium. ...

Turfgrass nutrient uptake may be differentially affected by different salts. The objective of this study was to compare nutrient uptake in tall fescue (Festuca arundinacea Schreb.) as affected by carbonate, chloride, and sulfate under iso-osmotic, iso-Na+ strength conditions. 'Tar Heel II' and 'Wolfpack' cultivars were subjected to NaCl, Na2CO3, Na2SO4, CaCl2, NaCl+ CaCl2, Na2CO3+ CaCl2, and Na...

We investigated the effect of exchanger inhibitory peptide (XIP) on Na-Ca exchange current (INa-Ca) in guinea pig ventricular cells. Cells were voltage-clamped with microelectrodes containing 20 mM Na+ and 14.0 mM EGTA ([Ca]i = 100 nM). An outward putative exchange current was stimulated when extracellular Na+ was reduced from 144 mM to zero (Li+ replaced Na+). This outward current showed a sig...

Mitochondrial Ca(2+) efflux is linked to numerous cellular activities and pathophysiological processes. Although it is established that an Na(+)-dependent mechanism mediates mitochondrial Ca(2+) efflux, the molecular identity of this transporter has remained elusive. Here we show that the Na(+)/Ca(2+) exchanger NCLX is enriched in mitochondria, where it is localized to the cristae. Employing Ca...