Effects of Prednisolone on Growth and Nucleic Acid Metabolism of Pekin Ducks

Abstract

INTRODUCTIONTHE adrenal corticosteroids are being used extensively for many therapeutic purposes. Although many gross effects are well known, their primary site or sites of action have not been elucidated. The results of numerous in vivo and in vitro experiments in recent years indicate rapid changes in nucleic acid metabolism after corticosteroid treatment.It has been established that corticosteroids stimulate protein synthesis within the liver (Weber et al., 1965), but depress protein synthesis and increase protein catabolism in extrahepatic tissues (Bethell et al., 1965). Effects of Cortisol treatment on increased RNA synthesis in rat liver was observed within 2–3 hours, followed 4–10 hours by increased protein synthesis (Lang and Sekeris, 1964). In tissues known to involute in response to glucocorticoids, e.g., the spleen and thymus, the synthesis of RNA was depressed (Feigelson, 1964). The rate of DNA synthesis was depressed by glucocorticoids to a greater degree than RNA…