The fortification of cereal grains with metal micronutrients is a major target to combat human malnutrition of Fe and Zn. Based on recent studies showing that N fertilization can promote Fe and Zn accumulation in cereal grains, we investigated here the influence of nitrate- or ammonium-based N fertilization on the accumulation of Fe, Zn, and Cu as well as metal chelator pools in flag leaves and...

A method involving surgical exposure of the colonic mucosa, fluorescent dye addition, and confocal microscopy has been developed for monitoring colonic crypt function in vivo in mice. Na(+) concentration in the extracellular pericryptal space of descending colon was measured using a low-affinity Na(+)-sensitive fluorescent indicator consisting of an Na(+)-sensitive chromophore (sodium red) and ...

Sodium overload of cardiac cells can accompany various pathologies and induce fatal cardiac arrhythmias. We investigate effects of elevated intracellular sodium on the cardiac action potential (AP) and on intracellular calcium using the Luo-Rudy model of a mammalian ventricular myocyte. The results are: 1) During rapid pacing, AP duration (APD) shortens in two phases, a rapid phase without Na(+...

The contribution of intracellular stores to axonal Ca 2 overload during chemical ischemia in vitro was examined by confocal microscopy. Ca 2 accumulation was measured by fluo-4 dextran (low-affinity dye, KD 4 M) or by Oregon Green 488 BAPTA-1 dextran (highaffinity dye, KD 450 nM). Axonal Na was measured using CoroNa Green. Ischemia in CSF containing 2 mM Ca 2 caused an 3.5-fold increase in fluo...

Na–K–Cl cotransporter isoform 1 (NKCC1) plays an important role in maintenance of intracellular Na , K , and Cl levels in astrocytes. We propose that NKCC1 may contribute to perturbations of ionic homeostasis in astrocytes under ischemic conditions. After 3– 8 hr of oxygen and glucose deprivation (OGD), NKCC1-mediated Rb influx was significantly increased in astrocytes from NKCC1 wild-type (NKC...

Poly(ADP-ribosyl)ation is a posttranslational modification of proteins, which is mainly catalyzed by poly(ADP-ribose) polymerase-1 (PARP-1) by using NAD(+) as substrate and is directly triggered by DNA strand breaks. Under mild genotoxic stress poly(ADP-ribose) (PAR) formation plays an important role in DNA repair whereas severe genotoxic stress and the ensuing overactivation of PARP-1 induce c...

The growth and tissue water, K(+), Na(+), Cl(-), proline and glycinebetaine contents of the shoots and roots of two Chenopodiaceae, Atriplex spongiosa and Suaeda monoica have been measured over a range of external NaCl salinities. Both species showed some fresh weight response to low salinity mainly due to increased succulence. S. monoica showed both a greater increase in succulence (at low sal...

Tonoplast vesicles were isolated from leaf mesophyll tissue of the inducible Crassulacean acid metabolism plant Mesembryanthemum crystallinum to investigate the mechanism of vacuolar Na+ accumulation in this halophilic species. In 8-week-old plants exposed to 200 mM NaCl for 2 weeks, tonoplast H+-ATPase activity was approximately doubled compared with control plants of the same age, as determin...

BACKGROUND Calcium-binding proteins that contain EF-hand motifs have been reported to play important roles in transduction of signals associated with biotic and abiotic stresses. To functionally characterize genes of EF-hand family in response to abiotic stress, an MtCaMP1 gene belonging to EF-hand family from legume model plant Medicago truncatula was isolated and its function in response to d...

Hypertension is linked to disturbed total-body sodium (Na ) regulation; however, measuring Na disposition in the body is difficult. We implemented Na magnetic resonance spectroscopy (Na-MR) and imaging technique (Na-MRI) at 9.4T for animals and 3T for humans to quantify Na content in skeletal muscle and skin. We compared Na-MRI data with actual tissue Na content measured by chemical analysis in...