* The extreme phenotype of zinc (Zn) hyperaccumulation, which is found in several Brassicaceae species, is determined by mechanisms that promote elevated Zn tolerance and high Zn accumulation in shoots. * We used reciprocal grafting between a Zn hyperaccumulator, Thlaspi caerulescens, and a Zn nonaccumulator, Thlaspi perfoliatum, to determine the relative importance of roots and shoots in Zn hy...

Salinity is an important constraining factor in the way of crop production around the world. Plant nutrition management could alleviate the harmful effects of salinity. In order to evaluate the interaction effects of Zinc availability and different levels of salinity, an experiment was conducted using four levels of zinc(0, 10, 20 and 40 mg/kg) and three levels of NaCl salinity of irrigation wa...

Two studies were conducted to investigate the possibility that pteroylmonoglutamic acid supplementation would alleviate teratogenesis in zinc-deficient rats. Pregnant rats of the Wistar strain were fed on Zn-deficient (less than 0.5 mg Zn/kg) or Zn-supplemented (75 or 95 mg Zn/kg) diets from mating until day 18.5 of gestation. The basal level of pteroylmonoglutamic acid added to all diets (0.56...

Zinc (Zn) is an essential, common metal in animal tissues. Zn levels were elevated in only four tissues after Zn administration, the highest increase being in the pancreas. Zn concentration was increased by metallothionein induction. Metallothionein-bound Zn significantly reduced the toxicity of the metals Cd, Cu and Hg. It should be noted that tissue Zn levels are different in experimental ani...

The effects of high Zn concentration were investigated in sugar beet (Beta vulgaris L.) plants grown in a controlled environment in hydroponics. High concentrations of Zn sulphate in the nutrient solution (50, 100 and 300 microm) decreased root and shoot fresh and dry mass, and increased root/shoot ratios, when compared to control conditions (1.2 microm Zn). Plants grown with excess Zn had inwa...

The possible coupling between regulation of the affinities for branchial Zn and Ca influx was investigated in juvenile rainbow trout Oncorhynchus mykiss acclimated to relatively hard fresh water ([Ca]=1.0 mmol l-1). The Km for branchial Ca influx was manipulated experimentally by exposing the fish to 2.3 micromol l-1 waterborne Zn for a total of 28 days. This procedure resulted in rapidly incre...

Cadmium (Cd) is a known hepato- and nephrotoxic pollutant and zinc (Zn) metalloproteins are important targets of Cd. Hence, the administration of Zn may mitigate Cd toxic effects. However, the interaction of Cd and Zn has been little investigated in the brain. Previously, we reported a protective effect of Zn on mortality caused by Cd in rats. Here, we tested whether the protective effect of Zn...

Zn(2+) plays an important role in diverse physiological processes, but when released in excess amounts it is potently neurotoxic. In vivo trans-synaptic movement and subsequent post-synaptic accumulation of intracellular Zn(2+) contributes to the neuronal injury observed in some forms of cerebral ischemia. Zn(2+) may enter neurons through NMDA channels, voltage-sensitive calcium channels, Ca(2+...

Zinc (Zn) is an essential micronutrient required by all cells but is toxic in excess. We have identified three allelic Zn-sensitive mutants of Arabidopsis (Arabidopsis thaliana). The gene, designated ZINC-INDUCED FACILITATOR1 (ZIF1), encodes a member of the major facilitator superfamily of membrane proteins, which are found in all organisms and transport a wide range of small, organic molecules...

Analysis of naturally occurring isotopic variations is a promising tool for investigating Zn transport and cycling in geological and biological settings. Here, we present the recently installed double-spike (DS) technique at the MAGIC laboratories at Imperial College London. The procedure improves on previous published DS methods in terms of ease of measurement and precisions obtained. The anal...