RESUMO
An attempt was made to analyse where and why stone formation in the kidney starts. For this purpose specific electrical conductivity (SEC) of the serum and urine of the same individual in 50 cases of stone formers (Group I) and 50 controls (Group II) was measured. The mean serum value of SEC at 37 degrees C and 50 Hz in mu mho/cm of Group I was 1.23 x 10(4), while that of Group II was 1.20 x 10(4). This was not statistically significant. However, urinary SEC values did differ significantly between the 2 groups. An analysis of observations reveals that in the case of stone formers there is a fault in the solute transfer system in the kidney at the membrane level (urothelium).
Assuntos
Cálculos Renais/etiologia , Adulto , Condutividade Elétrica/fisiologia , Epitélio/fisiopatologia , Feminino , Humanos , Cálculos Renais/sangue , Cálculos Renais/urina , Túbulos Renais/fisiopatologia , MasculinoRESUMO
To study the mechanism of hypercalciuria in metabolic acidosis, ammonium chloride loading (long) test was performed in 68 stone formers and 50 controls. Administration of ammonium chloride in both stone formers and controls produced a significant increase in urinary volume, ammonium and calcium excretions, no change in plasma calcium and creatinine clearance and significant decrease in plasma bicarbonate. However, on the third day of ammonium chloride loading test, urinary ammonium excretion and plasma bicarbonate levels were significantly lower while urinary calcium excretion was significantly greater in stone formers than in controls. Thus calciuresis could be correlated with the degree of metabolic acidosis but not with the rate of urinary ammonium excretion.
Assuntos
Acidose/urina , Cálcio/urina , Cloreto de Amônio/farmacologia , Bicarbonatos/sangue , Feminino , Humanos , Masculino , Compostos de Amônio Quaternário/urina , Cálculos Urinários/urinaRESUMO
Urinary hydrogen ion excretion has been studied in 68 adult stone formers and in 50 controls. Under basal state, the stone formers showed statistically significant higher urinary pH, and lower 24-hour urinary titrable acid, ammonium and total hydrogen. On the 3rd day of ammonium chloride loading test, the stone formers showed statistically significant higher urinary pH and lower 24-hour urinary titrable acid, ammonium, total hydrogen and plasma bicarbonate. 'Clearance' indices of hydrogen ion excretion were also depressed in a great majority of the stone formers. The results indicate the frequent co-existence of defective urinary acidification with nephrolithiasis.
