Biomedical subjects
Publications and source records attributed to A Livne.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The effect of sodium chloride added to root medium of pea seedlings on respiratory activity of tissue segments and on isolated mitochondria was studied. Salinization enhances the respiration of leaves about one-third on a fresh weight, dry weight or protein basis. Roots and stems show only 10 to 15% respiratory stimulation. The onset of respiratory increase in leaves roughly parallels the increase in NaCl content and the decrease in growth rate. At a later stage the elevated respiration is apparent in treated plants even though the concentration of NaCl reaches a plateau and osmotic adjustment is being reached. Stimulation of respiration was found in both etiolated and green plants. Experiments with DNP show that simple uncoupling by salt is not involved; the respiratory increase in control and treated tissue is proportionally the same.In accordance with increased respiration rates observed in vivo, mitochondria from salt-treated plants show higher rates of oxygen uptake on several substrates. The effect of NaCl added during growth is long term and is distinct from the effect of NaCl added to mitochondria isolated from control plants. Since P/O ratios are not affected by NaCl, the potential for oxidative phosphorylation in salt-affected tissue appears to increase. It is postulated that this increase may lead to changes in ADP and ATP content, and in turn, affect regulation of metabolic pathways.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Kinetic and thermodynamic properties of red cell lithium (Li) efflux were examined in patients with essential hypertension; the maximal rate of Li efflux as affected by temperature was measured at the range of 12 degrees to 42 degrees C. Fifty-two patients with essential hypertension and 22 normotensives were studied. The mean Li efflux, both into sodium (Na) medium and Li-Na countertransport, was higher in hypertensive than in normotensive persons, but the distinction between the two groups was limited by extended scatter and overlap. The distinction could be markedly improved by determining the effect of temperature on Li efflux. While all the normotensives exhibited Arrhenius plots of Li efflux with a change in slope ("break") around 30 degrees C, the corresponding "break" for most (75%) of the hypertensives was about 20 degrees C. Consideration of both the rate and the temperature dependence of Li efflux further improved the differentiation of hypertensive patients. Analysis of normotensive offspring of hypertensives and of patients with secondary hypertension indicates that the temperature dependence of Li efflux may serve as a genetic marker for essential hypertension.