CHANGES IN RENAL FUNCTION ACCOMPANYING THE HYPERTROPHY OF THE REMAINING KIDNEY AFTER UNILATERAL NEPHRECTOMY 1

Abstract

The functional changes which accompany the hypertrophy of the kidney remaining after unilateral nephrectomy were followed by the measurement of the glomerular filtra- tion rate (inulin clearance), effective renal blood flow (diodrast clearance) and tubular excretory mass (diodrast Tm). Changes in renal function comparable to the increase in kidney wt. known to occur after unilateral nephrectomy, have not previously been demonstrated. Renal function was studied following unilateral nephrectomy performed during the pregnancies of two [female][female]. In one patient, the removed kidney was apparently a functioning organ at the time of nephrectomy, while in the other the renal tissue had been almost completely replaced by a malignant tumor. Following the removal of a functioning kidney, the functional changes which took place may be summarized as follows. There was a rapid rise in glomerular filtration rate and effective renal blood flow and a much delayed increase in the mass of functioning tubular tissue (diodrast Tm). There was relative hyperemia of renal excretory tissue which persisted until the time when the compensatory hypertrophy of the tubular excretory tissue had been accomplished. The completion of this process required 2 yrs. Following the removal of a kidney previously destroyed by disease, these changes were not noted. The high figure for diodrast Tm demonstrated that hypertrophy must have occurred previous to operation. The increase in diodrast Tm in the remaining kidney after unilateral nephrectomy apparently parallels the morphologic hypertrophy of the kidney.