The electrogenic Na-K pump coupling ratio in the large neurons of the lobster cardiac ganglion was determined by two different electrophysiological techniques. A graphical analysis plotting exp(EmF/RT) vs. [K]o after the pump was blocked by ouabain was used to determine values for [K]i, PNa/PK, and the pump coupling ratio. These measurements were made 4-8 h after the cells were penetrated with ...

Milk samples were taken from 10 plains viscacha between 9 and 64 days post partum. Mean concentrations (+/- s.e.) were 17 +/- 1.1 mM-Na; 32 +/- 1.6 mM-K; 35 +/- 2.2 mM-Cl; 116 +/- 3.3 mM-lactose (total reducing sugar) (all in 8 samples); less than 10-220 mg citrate/l (range of 4 samples); 15.7 +/- 0.64 g total nitrogen/l (3 samples). The Na:K ratio was 1:1.95 +/- 0.17. It was estimated that the...

1. Two processes of Ruthenium Red-insensitive Ca2+ efflux exist in liver and in heart mitochondria: one Na+-independent, and another Na+-dependent. The processes attain maximal rates of 1.4 and 3.0 nmol of Ca2+.min-1.mg-1 for the Na+-dependent and 1.2 and 2.0 nmol of Ca2+.min-1.mg-1 for the Na+-independent, in liver and heart mitochondria, respectively. 2. The Na+-dependent pathway is inhibited...

Prostasin is a serine peptidase hypothesized to regulate epithelial sodium channel (ENaC) activity in animals or on in vitro cultured cells. We investigated whether urinary prostasin may be a candidate marker of ENaC activation in humans. We studied 10 healthy volunteers and 8 hypertensive patients with raised aldosterone-to-renin ratio before and after spironolactone or saline/Florinef suppres...

In the whole brain of rats, apomorphine in doses of 5-10 mg/kg elevated noradrenaline (NA) level 10-20 min after s.c. injection , but reduced NA level 60-90 min after injection in doses of 2-10 mg/kg associated with increased level of 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPGSO4). With 5 mg/kg of apomorphine, NA content in the pons+medulla oblongata and midbrain showed biphasic chan...

BACKGROUND Furosemide is a loop diuretic, which blocks the Na(+), K(+), 2Cl(-) cotransporter (NKCC2) in the thick ascending limb of Henle (TAL). By diminishing sodium (Na(+)) reabsorption, loop diuretics reduce the lumen-positive transepithelial voltage and consequently diminish paracellular transport of magnesium (Mg(2+)) and calcium (Ca(2+)) in TAL. Indeed, furosemide promotes urinary Mg(2+) ...

statins have antioxidant and anti-inflammatory effects that are not directly related to their cholesterol-lowering activity. this study aimed to investigate the effect of simvastatin on the extent of tissue damage in cisplatin-induced nephrotoxicity. simvastatin was orally given to rats in different doses (1, 2 and 4 mg/kg), 1 h prior to cisplatin injection (5 mg/kg, i.p.). all animals were dec...

In Ca-deficient smooth muscle of guinea-pig taenia coli, repeated application of high-K solution (45.4 mM) containing Ca induced contractions of similar shape and magnitude. In muscle treated by a Ca- and Mg-deficient solution, however, addition of Ca and K either did not induce contraction or induced only a delayed contraction. Ouabain (1 X 10(-3) M) also inhibited Ca- and K-induced contractio...

Swelling-activated [K-Cl] cotransport and shrinkage-activated Na/H exchange were studied in dog red cells with altered internal Mg or Li content. The two pathways responded in a coordinated fashion. When cells were depleted of Mg, [K-Cl] cotransport was stimulated and Na/H exchange was inhibited. Raising internal Mg had the opposite effect: [K-Cl] cotransport was inhibited and Na/H exchange was...