Our study supports the concept that proteinuria is an independent risk factor for the progression of renal disease. For patients with proteinuria of more than 1 g/d, we suggest a target blood pressure of less than 92 mm Hg (125/75 mm Hg). For patients with proteinuria of 0.25 to 1.0 g/d, a target mean arterial pressure of less than 98 mm Hg (about 130/80 mm Hg) may be advisable. The extent to which lowering blood pressure reduces proteinuria may be a measure of the effectiveness of this therapy in slowing the progression of renal disease.

No abstract

The relationship between plasma potassium concentration and the renin-angiotensin-aldosterone system was evaluated in ten patients with chronic renal failure (creatinine clearance 10–56 ml/min). Under basal conditions and following various stimulation maneuvers, normokalemic patients demonstrated normal plasma renin and aldosterone levels. Five of six patients with hyperkalemia had diminished function of the renin-angiotensin-aldosterone system; their ability to conserve sodium during salt depletion was less than that of normokalemic patients. The data suggest that the maintenance of plasma potassium levels in these patients is dependent on the presence of a normally functioning renin-angiotensin-aldosterone system; aldosterone activity may be an important determinant of sodium conservation in patients with renal failure.

No abstract

The effect of calcium chloride infusion on the renal handling of magnesium was evaluated in thyroparathyroidectomized dogs during normal and acute reduction in glomerular filtration rate. The results show that calcium infusion increased urinary magnesium even when the filtered load of magnesium was markedly reduced. The augmented magnesium excretion was associated with an absolute increase in calcium reabsorption. These observations indicate that calcium infusion reduces the tubular reabsorption of magnesium and is consistent with the concept that these two ions share and compete for a common reabsorptive pathway in the nephron. Sodium excretion also increased during chloride infusion but a comparison of the clearances of magnesium (C_Mg), sodium (C_Na) and calcium (C_Ca) indicates that C_Mg was more closely related to C_Ca than C_Na when calcium chloride was infused alone. With the addition of saline infusion, C_Mg became more dependent on C_Na