Cellular hypertrophy and renal function during compensatory renal growth.

Simultaneous measurements of biochemical and physiological events of compensatory renal hypertrophy were made in groups of white Spartan rats. Thirty hours following right unilateral nephrectomy, the left kidney had an increased rate of renal plasma flow, glomerular filtration rate, and potassium excretion when compared to sham-nephrectomized rats. Kidney cells were also hypertrophied as evidenced by an increase in the ratio of ribonucleic to deoxyribonucleic acid. The effects of a single injection of cycloheximide and actinomycin D on compensatory growth were studied. Both drugs prevented the rise in glomerular filtration rate and renal plasma flow 30 h postnephrectomy while having no inhibitory effect on cell hypertrophy. The maintenance of nephrectomized rats on a low-sodium diet also interfered with the physiological components of the response while having no effect on ribonucleic or deoxyribonucleic acid. These suggest that the physiological and biochemical aspects of compensatory renal hypertrophy may be under separate control systems.