Adaptational changes in renal vacuolar H(+)-ATPase in the rat remnant kidney

After 7/8 nephrectomy, the remnant kidney exhibits an adaptive increase in acid secretion per nephron. We studied the role of the kidney vacuolar H(+)-ATPase in this adaptational response by anti-H(+)-ATPase immunocytochemistry in kidneys from rats subjected to 7/8 nephrectomy or a sham procedure at 1, 2, and 3 wk after surgery. No changes in H(+)-ATPase staining were apparent in the proximal tubule, thick ascending limb, or distal convoluted tubule. In the cortical collecting ducts, the percentage of intercalated cells with well-polarized apical and well-polarized basolateral H(+)-ATPase staining was significantly higher in the remnant kidneys at 1, 2, and 3 wk. In the medullary intercalated cells of the sham-operated kidneys, relatively few cells had predominant plasma membrane H(+)-ATPase staining. In the remnant kidneys, the percentage of medullary intercalated cells with predominant plasma membrane H(+)-ATPase staining was increased significantly at 1 and 2 wk after surgery, returning to sham-operated values at 3 wk. The results indicate that intercalated cells in the collecting ducts of both cortex and medulla participate in the adaptation to reduction in renal mass by changing the steady-state distribution of H(+)-ATPase, similar to changes that occur with chronic acid administration.