Potassium activity and plasma membrane potentials in epithelial cells of toad bladder.

Intracellular potassium activity (aki), mucosal and serosal membrane potential (mEm, sEm), short-circuit current (Isc), and transepithelial potential difference in the epithelium of the toad bladder were measured with a potassium-sensitive liquid ion exchanger and an ordinary microelectrode. Under basal conditions, aki was 41.2 +/- 0.5 mM, corresponding to 54.4 mM in free potassium concentration, so half or more of the intracellular potassium may be of bound form or sequestrated within subcellular organelles. The sEm cannot be explained by only the potassium equilibrium potential (Eeq), because the sEm was markedly lower than the Eeq and no relation was found between them. Ouabain and rotenone decreased the aki, but ethacrynic acid, which also inhibited the Isc and the membrane potentials, did not show any effect on aki. Vasopressin decreased aki with an elevation in mEm, whereas prostaglandin E1 increased the aki with elevation in the sEm. These characteristic changes may afford an insight into the mechanisms by which transcellular electrolyte transport occurs.

Prediction of the effect of corticosteroid on idiopathic nephrotic syndrome based on a discriminant function.

For the purpose of discriminating between cases of nephrotic syndrome with and without corticosteroid effect, a linear discriminant function was applied in attempt to predict the effect of corticosteroid by the use of a computer. The parameters used were 15-min values of the PSP test, urinary protein, serum cholesterol, renal biospy findings, the number of red cells in the urinary sediment and immunoglobulin clearance ratio. The rate of correct prediction using the function with immunoglobulin clearance ratio was 87.0 %.

Laser photolysis and fluorescence studies on pyrene-thiazide and pyrene-diazoxide systems.

The laser photolysis studies on pyrene, pyrene-thiazides and pyrene-diazoxide systems in acetonitrile revealed that thiazides and diazoxide can scavenge the photoejected electron. It was found that the pyrene fluorescence is quenched by the present diuretics and related compounds and both static and dynamic quenching constants were obtained. Thiazides quench the fluorescence through both static and dynamic mechanism, while the small static quenching constant and no lifetime shortening of pyrene were observed in the case of diazoxide quencher. This difference may correspond to the difference of their diuretic activity.

A metal complexing property of furosemide and bumetanide: determination of pK and stability constant.

Furosemide and bumetanide have been found to have different pK values and undergo complex formation with several metal ions in dioxane-water solution. pK values of these diuretics were determined. Evidence for complex formation was provided by a drop in pH during complex formation, production of a characteristic color and precipitation.

Effect of colchicine on the osmotic water flow across the toad urinary bladder.

Osmotic water movement across the toad urinary bladder in response to both vasopressin and cyclic AMP was inhibited by 10(-5) to 10(-4) M colchicine on the serosal but not on the mucosal side. This inhibitory effect was found to be time- and dose-dependent. Colchicine alone did not change basal osmotic flow and a baseline of the short-circuit current (Isc) and also did not affect a vasopressin-induced rise of the Isc. The inhibitory effect was not prevented by the addition of pyruvate. The osmotic water movement produced by 360 mM Urea (mucosal), 360 mM mannitol (serosal) or 2 mug/ml amphotericin B (mucosal), was not affected by 10(-4) M colchicine. These results suggest that colchicine inhibits some biological process subsequent to the formation of cyclic AMP except a directional cytoplasmic streaming process where microtubules may be involved.

Hypokalemia and metabolic alkalosis resulting from overuse of magnesium oxide.

A 23 year old woman had taken large doses of magnesium oxide (up to 20 to 30g per day) initially for habitual constipation and later for idiopathic edema instead of diuretics, until the concealed abuse was discovered. During the abuse she showed hypokalemia and metabolic alkalosis. When the ingestion was stopped, the electrolyte imbalance recovered within two weeks.

Prognosis of chronic glomerulonephritis with special reference to hypertension and renal function.

Incidence of hypertension in chronic glomerulonephritis and its influence on the clinical course of the disease were studied using statistic technique, especially that of Markovian process. 1. Incidence of hypertension in a total of 283 cases was 15.2%, while in the patients of which renal function reduced to approximately one half of the normal was about 50%. 2. The average of blood pressure in this disease tends to elevate with the decrease in 15 minute value of PSP excretion test and with the increasing serum creatinine level, although the variations are large. 3. After a fall of renal function to approximately one-third of the normal, the rate of clinical course is markedly rapid. 4. The prognosis of the progressive type of chronic glomerulonephritis is obviously affected to be shorten by the presence of hypertension. 5. According to the results obtained by the Markovian approach, survival years of the patients with wide range of renal function can be predicted with relative accuracy.

Release of cyclic AMP by toad urinary bladder.

Cyclic AMP accumulates in the Ringer solution bathing the toad urinary bladder in vitro. At least 4 times more cyclic AMP is released into the solution bathing the serosal surface than into the solution bathing the mucosal surface. Most of the cyclic AMP originates in the epithelial cells rather than the stroma. Vasopressin increased the content of cyclic AMP in the epithelial cells and increases the amount of cyclic AMP in the Ringer solution. Since there is not an increase in medium cyclic AMP when cell cyclic AMP levels are increased by theophylline, it is suggested that theophylline may reduce the permeability of the cell membrane to cyclic AMP. Finally, it is demonstrated that 10 mM NaF increase the amount of cyclic AMP in the epithelial cells and in the solution bathing the bladder, but block the effect of vasopressin on water permeability, presumably at a step subsequent to the formation of cyclic AMP.

Prognosis of chronic glomerulonephritis in adult patients estimated on the basis of the Markov process.

The prognosis of chronic glomerulonephritis based on renal function was assessed using a statistical technique of the Markov process, where the absorbing state was assumed to be an uremic state, 194 adult patients with different types of disease were subjected to study. The 15 min value obtained in the intravenous PSP excretion test was divided into five states; SI (greater than 34%, normal), SII(25-34), SIII(15-24), SIV(5-14) and SV (greater than 5, uremic). The rates of SV with time were calculated with respect to several clinical characteristics. The prognosis of the patients with hypertension, distinct proteinuria and hematuria, or cellular cylindruria appeared to be relatively poor. The estimated number of years from each state to SV were also calculated. The results were similar to those already reported and gave us more exact information about the prognosis.