We compared sodium-calcium (Na-Ca) exchange in vascular smooth muscle between spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. Aortic rings of 11 SHR and 11 WKY rats aged 11-12 weeks were superfused with physiological saline, and isometric tension was measured. Systolic blood pressure was higher in SHR (174 +/- 12 mm Hg) than in WKY rats (132 +/- 4 mm Hg): 1) In the presence o...

Chronic metabolic acidosis increased the Na+-H+ exchange activity in isolated renal brush-border membrane vesicles. Treatment altered the initial rate of Na+ uptake by increasing Vm (acidotic, 15.3 +/- 0.7 nmol of Na+ X mg-1 X 2 s-1; normal, 11.3 +/- 0.9 nmol of Na+ X mg-1 X 2 s-1), and not the apparent affinity KNa+ (acidotic, 10.2 +/- 0.5 mM; normal 10.2 +/- 0.6 mM). Metabolic acidosis result...

An ATP-hydrolyzing activity with the properties of a Mg(2+)-dependent (Na(+),K(+))-ATPase (ATP phosphohydrolase, EC 3.6.1.3) from a 20-fold purified plasma membrane fraction of the marine diatom, Nitzschia alba is described. The basal activity requires Mg(2+) and further stimulation by Na(+) or Na(+) plus K(+) is dependent on the presence of Mg(2+); Mn(2+) or Co(2+) can partially substitute for...

This study investigated the effects of daily intraperitoneal injections of N-methyl-D-aspartate receptor antagonist MK-801 and nitric oxide synthase inhibitor nitro-L-arginine (L-NA) on the survival of retinal ganglion cells (RGCs) at 1 and 2 weeks after unilateral optic nerve transection in adult hamsters. The left optic nerves of all animals were transected intraorbitally 1 mm from the optic ...

Using first-principles calculations, we describe and compare atomistic lithiation, sodiation, and magnesiation processes in black phosphorous with a layered structure similar to graphite for Li-, Na-, and Mg-ion batteries because graphite is not considered to be an electrode material for Na- and Mg-ion batteries. The three processes are similar in that an intercalation mechanism occurs at low L...

Maximal activation of a Na+-dependent adenosine diphosphate-adenosine triphosphate exchange reaction mediated by kidney microsomes was achieved at 0.1 mu and 0.4 mu Mg++ in the presence of 1.5 mM and 32 mM Na+, respectively. K+ inhibited the Na+-dependent exchange rate when lower concentrations of Na+ and Mg++ were used and stimulated it in the presence of 0.4 mM Mg++ and 32 mM Na+. The inhibit...

High dietary sodium intake triggers increased blood pressure (BP). Animal studies show that dietary salt loading results in dermal Na+ accumulation and lymphangiogenesis mediated by VEGF-C (vascular endothelial growth factor C), both attenuating the rise in BP. Our objective was to determine whether these mechanisms function in humans. We assessed skin electrolytes, BP, and plasma VEGF-C in 48 ...

1 Methimazole (1-methyl-2-mercaptoimidazole, MMI) and propylthiouracil (6-propyl-2-thiouracil, PTU) which are used in the therapy of hyperthyroidism were found to reduce brain noradrenaline (NA) content. Endogenous NA levels in rat brain were reduced from 1 to 6 h after intraperitoneal injection of MMI by doses in excess of 25 mg/kg and by PTU at a dose of 50 mg/kg. However, endogenous NA in th...