Glomerular function and morphology after renal mass reduction in dogs.

To determine whether the proteinuria, glomerular sclerosis, and decline in glomerular filtration rate (GFR) described in rodents after renal mass reduction develop in another species, 24-hour proteinuria, glomerular structure, and fasting and postfeeding GFR were examined in dogs subjected to seven-eighths reduction in renal mass. All dogs were fed a diet containing 26% protein. Six dogs with a GFR less than 10 ml/min (8% to 17% of control two-kidney GFR) were killed within 6 months after renal mass reduction. Twenty-four-hour urinary protein excretion was modestly although definitely increased (236 +/- 26 mg/24 hr, P less than 0.01). All remnant kidneys demonstrated structural changes of mesangial hyperplasia or focal glomerular sclerosis. Ten dogs with a remnant kidney and early GFRs 16% to 39% of control values were followed for 18 to 39 months. In seven dogs, GFR showed little tendency to decrease with time. In one of them, proteinuria was 106 mg/24 hr with normal-appearing glomeruli at 14 months. In three dogs, proteinuria was progressive, averaging about 1 gm/24 hr at 18 months and 2 gm/24 hr at 24 to 34 months; glomerular pathologic findings progressed from focal mesangial hyperplasia or focal glomerular sclerosis at 8 to 16 months to focal and segmental sclerosis or diffuse glomerular obsolescence at 25 to 34 months; and fasting GFR progressively declined starting at 21 to 24 months after renal mass reduction.(ABSTRACT TRUNCATED AT 250 WORDS)