Massive proteinuria and its effects on renal tubular functions

Studies of renal tubular functions were made in two groups of patients with biopsy-proven primary glomerulonephropathies to assess the effects of proteinuria on the tubules. Group I (n = 9) had had minimal proteinuria and Group II (n = 8) had massive proteinuria. At the time the studies were made, all patients were normotensive, free of oedema, and on no dietary or drug therapy; they had normal glomerular filtration rates, serum albumin and total protein concentrations. Patients in Group II had diminished urine concentrating ability, impaired acidifying mechanism, but elevated maximum tubular secretory capacity compared with patients in Group I.