Effect of Prednisolone on Synthesis of DNA and RNA by Human Lymphocytes in vitro

Abstract

THE ability of the extract of Phaseolus vulgaris, phytohaemagglutinin, to initiate the synthesis of ribonucleic acid (RNA), deoxyribonucleic acid (DNA) replication and cytokinesis in human lymphocytes in vitro is well known^1–3. It has recently been shown that the response of normal human lymphocytes to phytohaemagglutinin can be markedly altered by the serum which is used to bolster the culture medium¹. Of the sera which markedly depressed this response, some were obtained from patients with lymphocytic diseases; of these, many were treated with corticosteroids. We decided, therefore, to investigate the effects of corticosteroids on these cultures. Accordingly, we have measured the in vitro responsiveness initiated in normal human peripheral lymphocytes in the presence of increasing doses of prednisolone-21-phosphate by phytohaemagglutinin.