Rate of protein synthesis and polyribosome formation in the frog pancreas after fasting and feeding

Abstract

1. 1. The rate of incorporation of [14C]leucine into the proteins of the frog pancreas was measured after the animals had been fasted or fed. The incorporation rate increased after feeding, being maximal at about 4 h after the meal.

2. 2. In homogenates of pancreases from fasted frogs only monoribosomes and dimers were present. The absence of polyribosomes in the fasted pancreas was not due to enzymic degradation in the homogenate. After feeding, the appearance of heavy polyribosomal aggregates was observed. When the rate of incorporation was maximal, monoribosomes were almost completely absent.