Chemical aspects of compensatory renal hypertrophy.

Abstract

Summary The effect of unilateral nephrectomy on the size and composition of the remaining kidney has been investigated in rats. In normal rats the right kidney is, on the average, significantly heavier than the left and has a higher total content of DNA and RNA.1 The 2 kidneys have almost identical ratios of RNA/DNA and protein/DNA. After unilateral nephrectomy the surviving kidney increases steadily in wet and dry weight for the 1st 4 days after the operation. This is accompanied by a much slower increase in total DNA content and by a dramatic increase in RNA/DNA ratio. The RNA/DNA ratio in kidney is also affected by diet, being higher on a high-protein than on a low-protein intake. Moreover, the rise in RNA/DNA ratio that follows unilateral nephrectomy is greater in animals fed a high-protein diet. The changes in kidney weight and in total contents of DNA, RNA, protein, and lipid phosphorus resulting from the feeding of a high-protein diet were found to be of approximately the same magnitude as those in the remaining kidney 4 days after unilateral nephrectomy. The RNA/DNA and protein/DNA ratios are also greater in rats fed a diet containing 10% urea, but the increase is much less than that in the remaining kidney after unilateral nephrectomy.