AND GERHARD GIEBISCH. Potassium secretion by distal tubule after potassium adaptation. Am. J. Physiol. 22 l(2) : 437-448. 197 1 .-The renal contribution to the tolerance to acute loads of potassium conferred by a chronic high-K intake was examined in rats. Changes in sodium and potassium excretion following acute K infusion were observed in animals fed normal, high-K, low-Na, or low-K diets. Co...

aminul islam1*, jatish chandrabiswas 1, a. j. m. sirajul karim2, mst. salmapervin3, and md. abu saleque4 1*-soil science division, bangladesh rice research institute, gazipur-1701, bangladesh 2-department of soil science, bangabandhu sheikh mujibur rahman agricultural university, salna, gazipur-1706, bangladesh 3-plant physiology division, bangladesh rice research institute, gazipur-1701, bangl...

Some biological aspects of semen were investigated in the Persian sturgeon, Acipenser persicus, by determination of seminal plasma indices (ionic composition and osmolality), sperm density and their relationships with sperm motility. The osmolality of seminal plasma ranged from 42.00 to 111.00 mOsmol Kg-1. The concentrations of Sodium (Na+), Potassium (K+), Chloride (Cl-), Calcium (Ca2+) and Ma...

In addition to the classic and well-established "feedback control" of potassium balance, increasing investigative attention has focused on a novel and not widely recognized complementary regulatory paradigm for maintaining potassium homeostasis-the "feed-forward control" of potassium balance. This regulatory mechanism, initially defined in rumen, has recently been validated in normal human subj...

Potassium release through ATP-sensitive potassium (K(ATP)) channels contributes to hypoxic vasodilation in the skeletal muscle vascular bed: It is uncertain whether K(ATP) channels on muscle cells contribute to the process. Potassium from muscle cells must cross the interstitial space to reach the vascular tissues, whereas that from vascular endothelium would have a higher concentration in veno...

The potassium cation (K) is fundamentally involved in myocyte metabolism. To explore the potential utility of direct MRI of the most abundant natural isotope of potassium, K, we compared K magnetic resonance (MR) image intensity with regional myocardial K concentrations after irreversible injury. Rabbits were subjected either to 40 minutes of in situ coronary artery occlusion and 1 hour of repe...

MALNIC, GERHARD, RUTH M. KLOSE, AND GERHARD GIEBISCH. Micropuncture study of renal potassium excretion in the rat: Am. J. Physiol. 206(4): 674-686. I g64.-Samples of proximal and distal tubular fluid were collected from rats maintained on a control, a low-K, or a high-K, low-Na diet. All animals received inulin-C 14. Plasma (P) and tubular fluid (TF) were analyzed for Na and K by dual-channel m...

We measured levels of potassium ion in the extracellular space of isolated superfused rabbit atria continuously with double-barreled microelectrodes of which on barrel was a K+ liquid ion-exchanger microelectrode and the other a potential-sensing micropipette. Increases in heart rate resulted in transient increases in extracellular potassium ([K+]0). When the quiescent atrium was stimulated the...

The actions of psoralens, benzofurans, acridinons and coumarins on the ionic currents in intact myelinated nerve fibres were investigated. All 6 substances blocked the potassium currents in a time-dependent manner, producing so-called K+ transients. Only 5-methoxypsoralen is a largely selective blocker of predominantly the axolemmal potassium channels, which is the characteristic required by ou...