Early changes in kangaroo lymphocytes stimulated with phytohaemagglutinin

Abstract

Kangaroo lymphocytes exposed to PHA show a rapid increase in the rate of synthesis of RNA; labelled RNA is at first confined to the nucleus, but soon appears in the cytoplasm. This is followed by increases in the rate of incorporation of 3H-phenylalanine, in nuclear and cytoplasmic volume, and in nuclear dry mass. DNA synthesis in cultures of kangaroo lymphocytes exposed to PHA occurs 12 h earlier than in similar cultures of human lymphocytes, and it is suggested that this is due to the earlier onset of protein synthesis in the marsupial lymphocytes.