EFFECT OF MORPHINIZATION ON IN VITRO INCORPORATION OF LABELLED PRECURSORS INTO ADRENAL PROTEIN AND NUCLEIC ACIDS IN RATS

In vitro incorporation of radioactive precursors into protein or nucleic acids and corticosterone production in the adrenals of morphine treated rats were examined, and the results were compared with those of ACTH treatment. An increase in incorporation of radioactive precursors into nucleic acids with concomitant decrease in corticosterone production was observed with repeated morphine treatment, indicating an enhanced synthesis of nucleic acids in the glands. On the other hand, incorporation of labelled amino acids into protein decreased after an initial increase. With repeated ACTH treatment, decreased incorporation of labelled precursors was observed in both protein and nucleic acids in parallel with the gradual increase in the rate of corticosterone production during the course of ACTH treatment. When adrenals were incubated with 5 μg/flask of corticosterone, the incorporation of radioactive precursors into nucleic acids was decreased markedly. These results suggest an interference of corticosterone which accumulates in the medium with the synthesis of nucleic acids in vitro.