Ouabain (0.05 millimolar) and low temperature (4 C) both caused the tissue Na(+) content of excised 5-day-old corn roots to increase, indicating that there is an inhibition of the Na(+) efflux pump. Na(+) efflux was measured utilizing three different methods. Each method gave similar results in terms of rate and ouabain sensitivity. With one of these methods, the compartmental efflux method, it...

Zea mays L. cv INRA 5a coleoptile segments ecidify the incubation medium on the addition of 1-naphthyl acetate (1-NA). The buffering capacity of the bathing solution increases during 1-NA stimulated medium acidification. The solution bathing the 1-NA treated coleoptile segment was analyzed by high performance liquid chromatography. A considerable amount of acetic acid was detected in the bathin...

The kidney plays a critical role in the regulation of inorganic phosphate (Pi) homeostasis through changes in the proximal tubular apical membrane Na-dependent Pi (Na/Pi) transport activity. In response to alterations in dietary Pi intake and during the aging process, changes in renal Na/Pi transport activity are inversely correlated with apical membrane cholesterol content. Cholesterol regulat...

We investigated the relationship between body size, Na(+)-K(+)-ATPase molecular activity, and membrane lipid composition in the kidney of five mammalian and eight avian species ranging from 30-g mice to 280-kg cattle and 13-g zebra finches to 35-kg emus, respectively. Na(+)-K(+)-ATPase activity was found to be higher in the smaller species of both groups. In small mammals, the higher Na(+)-K(+)...

Laser induced breakdown spectroscopy (LIBS) has become a powerful tool for the direct analysis of a large variety of materials in order to provide qualitative and/or quantitative information. However, there is a lack of information for LIBS analysis of agricultural products. In this work a LIBS system has been designed for the discrimination of Ca, Cu, Fe, and Na elements in Gannan Navel orange...

Monoamine oxidase (MAO, type A and B) and semicarbazide-sensitive amine oxidase (SSAO) metabolize biogenic amines, however, the impact of these enzymes in arteries from patients with type 2 diabetes remains poorly understood. We investigated the kinetic parameters of the enzymes to establish putative correlations with noradrenaline (NA) content and patient age in human mesenteric arteries from ...

1. Oxidative mechanisms have been implicated in neonatal cardiomyocyte hypertrophy. We and others have shown that a HMG-CoA reductase inhibitor preserves endogenous antioxidant enzyme activity and inhibits cardiac hypertrophy in vivo. We therefore have examined whether noradrenaline (NA) induces the generation of reactive oxygen species (ROS) during its induction of neonatal cardiomyocyte hyper...

The activities of both sarcolemmal (SL) Na(+)-K(+)-ATPase and Na(+)/Ca(2+) exchanger, which maintain the intracellular cation homeostasis, have been shown to be depressed in heart failure due to myocardial infarction (MI). Because the renin-angiotensin system (RAS) is activated in heart failure, this study tested the hypothesis that attenuation of cardiac SL changes in congestive heart failure ...