Effects of early undernutrition and subsequent refeeding on alkaline ribonuclease activity of rat cerebrum and liver.

The effect of undernutrition and subsequent rehabilitation on free and total alkaline ribonuclease activity (RNase) of cerebrum and liver was studied in 14- and 21-day-old rats. Free RNase activity was higher in both organs at 14 and 21 days of age. However, at day 21 the difference was statistically significant only in liver. Total RNase activity was not changed by undernutrition in cerebrum and was reduced in liver. Nutritional rehabilitation returned both free and total RNase activities to control levels in liver but had no apparent effect on cerebrum. The elevation of free RNase seems to be secondary to a reduced concentration of inhibitor protein and not to de novo synthesis of RNase.