Hurtado, Jose, Salvador Borges, and Martin Wilson. Na -Ca exchanger controls the gain of the Ca amplifier in the dendrites of amacrine cells J Neurophysiol 88: 2765–2777, 2002; 10.1152/jn.00130.2002. We have previously shown that disabling forward-mode Na -Ca exchange in amacrine cells greatly prolongs the depolarization-induced release of transmitter. To investigate the mechanism for this, we ...

The flash-induced Ca(2+)- and Na(+)-influx and Na+/Ca(2+)-exchange activity in blowfly Calliphora photoreceptors were investigated. The change in membrane potential, induced by a bright flash, was intracellularly measured in vivo. Based on a biophysical photoreceptor model, the Na(+)- and Ca(2+)-currents and concentration changes were determined from the first transient depolarization phase of ...

Calcium has a fundamental role in the cellular processes of ion absorption and retention. The ion is generally credited with lhaving beneficial effects on the semipermeability of membranes and structure of protoplasm (9,12). The electron microscope shows Ca deficiency to result in (lisorganization of membrane structure (19). In addition, the presence of calcium in solution was found by Viets (2...

Months after sacral spinal transection in rats (chronic spinal rats), motoneurons below the injury exhibit large, low-threshold persistent inward currents (PICs), composed of persistent sodium currents (Na PICs) and persistent calcium currents (Ca PICs). Here, we studied whether motoneurons of normal adult rats also exhibited Na and Ca PICs when the spinal cord was acutely transected at the sac...

The properties of Na-Ca-K exchange current through the plasma membrane of intact rod outer segments (ROS) isolated from bovine retinas were studied with the optical probe neutral red. Small cellular organelles such as bovine ROS do not offer an adequate collecting area to measure Na-Ca-K exchange currents with electrophysiological techniques. This study demonstrates that Na-Ca-K exchange curren...

one of the main aims of water resource planners and managers is to estimate and predict the parameters of groundwater quality so that they can make managerial decisions. in this regard, there have many models developed, proposing better management in order to maintain water quality. most of these models require input parameters that are either hardly available or time-consuming and expensive to...

Immunological stimulation of rat mucosal-type mast cells (RBL-2H3 line) by clustering of their Fce receptors (FceRI) causes a rapid and transient increase in free cytoplasmic Ca ion concentration ([Ca]i) because of its release from intracellular stores. This is followed by a sustained elevated [Ca]i, which is attained by Ca 21 influx. Because an FceRIinduced increase in the membrane permeabilit...

Recent evidence suggests the expression of a Na/ Ca exchanger (NCX) in vascular endothelial cells. To elucidate the functional role of endothelial NCX, we studied Ca signaling and Ca-dependent activation of endothelial nitric-oxide synthase (eNOS) at normal, physiological Na gradients and after loading of endothelial cells with Na ions using the ionophore monensin. Monensin-induced Na loading m...

Recent evidence suggests the expression of a Na(+)/Ca(2+) exchanger (NCX) in vascular endothelial cells. To elucidate the functional role of endothelial NCX, we studied Ca(2+) signaling and Ca(2+)-dependent activation of endothelial nitric-oxide synthase (eNOS) at normal, physiological Na(+) gradients and after loading of endothelial cells with Na(+) ions using the ionophore monensin. Monensin-...