It has been hypothesized that nitrate (NO(3)(-)) nutrition might induce iron (Fe) deficiency chlorosis by inactivation of Fe in the leaf apoplast (H.U. Kosegarten, B. Hoffmann, K. Mengel [1999] Plant Physiol 121: 1069-1079). To test this hypothesis, sunflower (Helianthus annuus L. cv Farnkasol) plants were grown in nutrient solutions supplied with various nitrogen (N) forms (NO(3)(-), NH(4)(+) ...

fifteen kinds of local wetland plants in taihu lake region of china were investigated on their respective growth conditions, biomass allocations and nutrient uptake capacities. the test plants were cultured in 3 l nutrient solutions for 28 days with nh4 +-n, no3 --n and p concentrations of 38.5, 132.8 and 10 mg/l, respectively. mean species total biomass ranged from 1.2-21.6 g/plant with a...

in this study the uptake and metabolism of adenosine by mitochondria has been investigated. incubation of cem cells mitochondria preparation with [3h] -adenosine showed substantial uptake and metabolism of adenosine. adenosine was both anabolized to amp, adp and atp, and also catabolized to inosine. the highest concentration of metabolites in extracted mitochondria was due to amp. the mitochond...

The purpose of this study was to establish the existence of Na/H exchange in cardiac muscle and to evaluate the contribution of Na/H exchange to pHi regulation. The kinetics of pHi changes in cultured chick heart cells were monitored microfluorometrically with 6-carboxyfluorescein and correlated with Nai content changes analyzed by atomic absorption spectrophotometry; transmembrane H+ movements...

Uptake of copper complexes by fish was studied by exposing neon tetras (Paracheirodon innesi) to solutions containing different concentrations of copper complexed to EDTA, diaminoethane, oxalic acid, or tartaric acid, while other copper species were kept at low and constant levels. The distribution of the copper species in the solution was quantified using chemical equilibrium modeling. It was ...

Most of the thallium uptake by canine iliac arteries (70%) was inhibited by ouabain. The component sensitive to ouabain was significantly increased by incubating tissues in K+-free solution and reduced by low temperatures, metabolic inhibitors, and loading with lithium. The apparent Km for thallium for the ouabain-sensitive uptake was 0.47 +/- 0.046 mM. External K+ inhibited thallium uptake and...

59Fe uptake by rabbit reticulocytes from human transferrin-bound iron was studied by using transferrin solutions (35, 50, 65, 80 and 100% saturated with iron) whose only common characteristic was their content of diferric transferrin. During the early incubation period, 59Fe uptake from each preparation by reticulocytes was identical despite wide variations in amounts of total transferrin, tota...

Nitrogen (N) uptake by fine roots of trees is important for understanding root physiological function in forest ecosystems. However, direct investigations situ ammonium and nitrate rates are limited. Thus, we aimed to clarify inorganic N among tree species determine the factors controlling through relationships with traits cool temperate coniferous forests. Using a solution depletion method mea...

Brain uptake of radiolabeled D and L-lactate, D-glucose and nicotine, as measured by the intra-carotid bolus method, was examined over a range of pH of the injected solution. The uptake of L-lactate was highest at pH 6.1, and lowered significantly at pH 7.2, 7.5 and 8.4. In contrast, the uptake of the D-enantiomer was not as dramatically affected. Glucose uptake was not affected by alterations ...

the present study was carried out to investigate three different adsorbents; dry cells of thebacterium exiguobacterium sp. 27, polyaniline and a mixture of both in different ratios for removal of ni(ii)from aqueous solution. the results showed that the adsorption of ni(ii) using dry cells of exiguobacteriumsp. 27 was very fast and the equilibrium time was 15 min, while the equilibrium time for ...