Mg2+ ions are very effective at stabilizing tertiary structures in RNAs. In most cases, folding of an RNA is so strongly coupled to its interactions with Mg2+ that it is difficult to separate free energies of Mg2+-RNA interactions from the intrinsic free energy of RNA folding. To devise quantitative models accounting for this phenomenon of Mg2+-induced RNA folding, it is necessary to independen...

Prostaglandins have diverse effects on renal electrolyte reabsorption, inhibiting NaCl absorption in the thick ascending limb and modulating sodium and calcium transport in cortical collecting cells. It is unclear what effect, if any, prostaglandins have on tubular magnesium handling. The effects of prostaglandin E2(PGE2) were studied on immortalized mouse distal convoluted tubule (MDCT) cells ...

The mechanisms of magnesium (Mg2+) transport, the regulation of intracellular Mg2+ concentrations and the relationship between Mg2+ and Ca2+ signaling during the stimulus-secretion coupling process in pancreatic acinar cells and other secretory epithelia are reviewed in this article. Our results demonstrate the existence of a Na+- and ATP-dependent transport system for Mg2+ extrusion from Mg2+-...

Magnesium (Mg2+) is indispensable for many physiological processes in the cell impacting organ function (de Baaij et al. 2015). Intracellular concentrations of free Mg2+ aremaintained within a narrow range (0.5–1.2 mM) through tightly regulated Mg2+ influx and effluxmechanisms (Ebel & Gunther, 1980). InhibitionofMg2+ effluxby substitution of extracellular Na+ by choline in mammalian cells indic...

Na+/Mg2+ antiport and Na(+)-independent Mg2+ efflux were investigated in erythrocytes of 41 patients with cystic fibrosis and 26 controls. Na(+)-independent Mg2+ efflux was unchanged in cystic fibrosis, but a significantly increased activity of Na+/Mg2+ antiport was detected (control: 0.16 +/- 0.02, cystic fibrosis: 0.39 +/- 0.06, Mg2+ efflux, mmol/30 min x 1 cells, mean +/- SEM, p < 0.01). An ...

Phosphatidylinositol 3-kinase (PI3K) has been implicated in low extracellular Mg2+ concentration ( [Mg2+]e)-induced aortic contraction, and Mg2+ deficiency has been associated with hypertension. Moreover, arterial PI3K activity is increased in hypertensive deoxycorticosterone (DOCA)-salt rats. We hypothesized that low [Mg2+]e activates PI3K, eliciting enhanced vascular contraction, PI3K activit...

In Retzius neurones of the medicinal leech, Hirudo medicinalis, kainate activates ionotropic glutamate receptors classified as AMPA/kainate receptors. Activation of the AMPA/kainate receptor-coupled cation channels evokes a marked depolarization, intracellular acidification, and increases in the intracellular concentrations of Na+ ([Na+]i) and Ca2+. Qualitatively similar changes are observed up...

To elucidate the mechanisms involved in Mg2+ transport at the apical and basolateral poles of the renal tubular epithelium, apical and basolateral plasma membrane vesicle preparations were derived from kidney tissue of freshwater- and seawater-adapted Mozambique tilapia Oreochromis mossambicus. Brush-border preparations were enriched 15.8-fold in alkaline phosphatase activity and consisted almo...

Euglena gracilis, Nutrition, Magnesium Deficiency, Magnesium Transport In order to obtain a model which allows to directly study Mg2+ influx into the cell, Mg2+ deficiency was induced in the unicellular photoautotrophic flagellate Euglena gracilis. Lack of Mg2+ in the culture medium leads to a number of morphological, biochemical, and physio­ logical changes in Euglena gracilis. The rate of cel...

Insulin has been shown to be a magnesium-conserving hormone acting, in part, through stimulation of magnesium absorption within the thick ascending limb. Although the distal convoluted tubule possesses the most insulin receptors, it is unclear what, if any, actions insulin has in the distal tubule. The effects of insulin were studied on immortalized mouse distal convoluted tubule (MDCT) cells b...