Prostaglandin-dependent osmotic water permeability of the frog and trout urinary bladder.

Washout of autacoids from serosal Ringer solution, using a repeated change of the solution of the frog and trout urinary bladder, was accompanied by a pronounced rise in the osmotic water permeability: the water transport in the frog rose from 0.05 +/- 0.02 to 1.

Evolutionary physiology: history, principles.

1) The history of comparative and evolutionary physiology since the early XIX century is given; 2) The methods of evolutionary physiology are described; 3) Principles of the evolution of function are discussed at every level of physiological organization (cellular, functional units of the organ, the organ itself, functional systems) as they apply to the kidney and to the regulation of salt and water balance; and 4) General questions of evolutionary physiology covering physico-chemical factors in evolution of functions, the development of the integrity of an organism, the origin of physiological adaptation, the development of interconnection of physiological systems are discussed.

Lithium transport in the chicken and marine teleost kidney.

The clearance ratio-C(Li)/C(ln) (Excretion Fraction of Lithium-EFLi) in the cod (Gadus morrhua L.) kidney amounts to 15.1 +/- 4.

On the correlation between individual biochemical parameters of human blood serum following space flight and their basal values.

The article presents data concerning the osmolality and concentration of electrolytes and hormones regulating their balance for blood serum of 223 cosmonauts and astronauts. The obtained results allow us to judge the constancy of physicochemical parameters for the blood serum of healthy individuals and how they react to extreme conditions of space flight. The parameters used for evaluation included not just absolute values for the examined indices, but also how they responded to space flight, the dependence on baseline values and the interrelationship between ions.

Does the gradual hydroosmotic response to antidiuretic hormone depend on intracellular cAMP accumulation or on the formation of intramembrane particle aggregates?

In experiments on frog urinary bladder the mechanisms behind the gradual development of a hydroosmotic reaction to antidiuretic hormone (ADH) were investigated. It was suggested that the velocity of hydroosmotic reaction may be limited by (a) formation and insertion of particle aggregates into the apical membrane or (b) by velocity of cAMP formation. The urinary bladders were exposed to 23 nM ADH for different times (from 1 to 20 min) and water flow was measured over a period of 40 min.

Vasopressin V1-antagonist increases the hydroosmotic response to arginine vasopressin in frog urinary bladder.

V1-antagonist, [Mca1, D-Phe2, Sar7] arginine vasopressin, at a concentration 0.5 nM to 5 nM increased hydroosmotic effect of 5 nM arginine vasopressin in frog urinary bladder. 1 nM V1-antagonist [Mca1, O-Me-Tyr2] arginine vasopressin does not changed hydroosmotic effect of 0.

Mechanism of postflight decline in osmotic concentration of urine in cosmonauts.

The ratio of reabsorption of osmotically free water to osmolal clearance in individual urine voids was about the same before and after short-term spaceflights (the points fall on the same regression line). This ratio was reduced after long-term flights, so that the regression lines for pre- and postflight values have different slopes. This change in the function relating the two factors was accompanied by increased vasopressin in blood plasma and probably was caused by altered cellular reaction to vasopressin.

The influence of amlodipine and verapamil on ion and water transport in the nephron, skin and urinary bladder of amphibians.

1. The addition of amlodipine or verapamil into the lumen of the newt distal tubule led to the decrease of reabsorption of Na, Cl, Ca and of fluid. 2.

Reversible inactivation of water and sodium transport systems in frog urinary bladder and skin in the presence of detergents.

Detergents (Triton X-100, dodecyl sulphate, saponin) added in concentrations of 0.1-10 mg/ml to solution at the outer frog skin surface reversibly reduced potential difference (PD) and short-circuit current (Isc); when added at the inner surface. Triton X-100 initially induced a short increase in the PD and Isc followed by a pronounced decrease similarly as after the application of any of the detergents used.

Cisplatin: nephrotoxic action in vertebrates and its prevention.

1. The kidney of frog and black sculpin appeared to be much less sensitive to the toxic action of CP in comparison with rat and pigeon. 2.

Water and sodium transport: effects of calcium channel blocker and calmodulin antagonists on the apical and basolateral membranes of amphibian epithelia.

Ca2+ channel blocker (sensit) and calmodulin antagonists (thioridazine, perphenazine, oxyprothepine) applied to the mucosal side of frog urinary bladder, weakened the response of epithelial cells to vasopressin. Thioridazine (2.7 X 10(-5) mol X l-1) and sensit (1.

The influence of furosemide and Co2+ on electrolyte and water transport in newt distal tubule and frog skin.

The technique of stationary microperfusion of the early distal tubule used in experiments on male newts (Triturus vulgaris) revealed the intratubular effect of CoCl2 and furosemide on the ion transport. CoCl2 in concentration 5 X 10(-4) M increased Na and Cl reabsorption, reduced Ca, Mg and K reabsorption, and increased (TFexp/TFo)in from 1.14 +/- 0.

Cobalt-dependent stimulation of sodium transport in the amphibian skin and nephron.

One to ten millimolar CoCl2, when applied to the outer surface of the apical membrane of the frog skin (Rana temporaria), reversibly increased the potential differences and short-circuit current. These observations suggest that Co2+ may control the gating system of the sodium channel. In the kidney of the newt (Triturus vulgaris), proximal reabsorption is increased under the influence of 0.

Specific vacuolation of frog urinary bladder granular cell after ADH stimulation of water transport.

The present study deals with an analysis of specific traits of cell vacuolation induced by water flow and ADH. During incubation of frog urinary bladders in Ringer's solution diluted 2-fold, the water content of the bladder wall increased by an average of 19%. In case of ADH-stimulated water flow the water content increased by an average of 15.

Fluid-electrolyte metabolism and renal function of white rats in experiments aboard Cosmos biosatellites.

Rat experiments on the Cosmos biosatellites demonstrated that the percentage of renal excretion of consumed water after flight was lower than after synchronous experiment. This can be attributed not only to water retention but also to a different level of extrarenal losses postflight. Weightless rats showed increased sodium excretion after water load tests and increased potassium excretion after potassium load tests.

Volume and ion regulating renal functions in the big gerbil (Rhombomys opimus L.) and the water vole (Arvicola terrestris L.).

1. After iso-osmotic salt loading (1% NaCl, 1.25% KCl, 0.