Hypothalamic histaminergic tuberomammillary (TM) neurons express nicotinic acetylcholine receptors (nAChRs) with kinetic and pharmacological properties resembling those of highly Ca(2+) permeable alpha7 nAChRs. However, the Ca(2+) permeability of TM nAChR channels has not been determined. To directly evaluate the Ca(2+) permeability of TM nAChRs, patch-clamp recordings were conducted using non-...

a hydroponic experiment was conducted to evaluate the effects of salt stress on safflower genotypes under greenhouse conditions. the experiment was arranged as a factorial one based upon a completely randomized design with three replications. five safflower genotypes (arak2811, nebraska10, sod25, ca116, and ca128), and four salinity treatments (0, 0.3, 0.5, and 0.7 percent of nacl) were employe...

  In a three-year (2004-2006), field experiment, we aimed to study changes in leaf physiological traits (leaf water potential-Ψleaf, leaf water content-LWC, carbon isotope discrimination-Δ, specific leaf area-SLA, chlorophyll content as assessed by SPAD and modified SPAD-MSPAD) and elemental composition (K, Na, Ca, Mg, K/Na, Ca/Mg, total leaf salinity-TLS) of sugar beets (cv. Rizor) grown unde...

There are a wide range of responses of plants to salinity which involve interactions of Na with Ca. Plant processes such as growth, photosynthesis, mineral nutrition, water and ion transport are affected by these Na-Ca interactions. Many of these responses can be linked to the direct Na-Ca interactions at the surface of the plasma membrane and subsequent Ca signaling events. 10.1. General Effec...

We have investigated the kinetics of mitochondrial Ca(2+) influx and efflux and their dependence on cytosolic [Ca(2+)] and [Na(+)] using low-Ca(2+)-affinity aequorin. The rate of Ca(2+) release from mitochondria increased linearly with mitochondrial [Ca(2+)] ([Ca(2+)](M)). Na(+)-dependent Ca(2+) release was predominant al low [Ca(2+)](M) but saturated at [Ca(2+)](M) around 400muM, while Na(+)-i...

We present high resolution spectral observations of the absorption lines of Ca II and Na I associated with the circumstellar disk surrounding the starβ Pictoris. The observations were taken over a four night period in January 1996 and reveal substantial profile variability between successive nights. High velocity absorption features at velocities of +58 km s−1 were observed in the Ca II data, b...

Electrolyte fluxes are fundamental to normal endocrine pancreatic function. Adenosine triphosphatases (ATPases) are enzyme systems believed to modulate electrolyte movements across membranes in a number of cell types. This study was undertaken to measure cation-dependent ATPases of rat pancreatic islets. In addition, we compared effects of substances which influence endocrine pancreatic functio...

X-ray microanalysis of freeze-dried labial gland cryosections revealed that Na concentration was doubled and the Ca/S concentration ratio was decreased in secretory granules of labial glands from patients with cystic fibrosis (CF) when compared with glands from normal subjects. Other results suggested that the decrease in the Ca/S concentration ratio resulted from an increase in S concentration...