The proportion of ribosomes engaged in rat pancreatic polysomal structures as influenced by pilocarpine injection.

Rats intravenously injected with pilocarpine at a concentration of 4 mg per 100 g body weight were killed after various time intervals and the relative numbers of ribosomes per cell active in protein synthesis were determined. It was found that until 1 h after pilocarpine injection there is a significant decrease in the number of ribosomes engaged in protein synthesis, whereas 2--3 h after pilocarpine injection, the number of active ribosomes equals that of control animals. After a short incubation in vitro, the same relative number of active ribosomes is always found, independent of the value determined in the pancreas directly after the death of the animal.