Protein Synthesis in Megaloblastic Erythropoiesis caused by Vitamin B₁₂ Deficiency

Abstract

LITTLE information is available about protein synthesis in the megaloblasts of pernicious anaemia. In experimental animals deprived of vitamin B₁₂, however, depressed protein synthesis has been demonstrated both in vivo¹ and in cell cultures and cell free systems derived from deficient animals^1–3. The addition of cobamide co-enzymes to such in vitro systems enhances the incorporation of labelled amino-acids into proteins^2,3, while the addition of vitamin B₁₂ alone has little or no effect^3,4. Following the recent demonstration of a pile-up of megaloblasts in the G₂ stage of interphase in pernicious anaemia⁵, we decided to investigate the protein synthetic activity of these abnormal cells by autoradiography.