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December 12, 1959


JAMA. 1959;171(15):2103-2104. doi:10.1001/jama.1959.03010330065019

The mature erythrocyte consists of about 90% hemoglobin by dry weight; the remainder is stroma and an impressive array of enzymes. Some of these enzymes are concerned with oxygen and carbon dioxide transport while others may be vestiges of previous existence as a cell capable of division. Recent investigations have contributed to the understanding of the mechanisms involved in biosynthesis of various components of the red blood cell. Interest has been focused principally on the manner of hemoglobin synthesis.

Understanding of the biochemistry of heme synthesis had its inception in the discovery of Shemin and Rittenberg1 that glycine labeled with isotopic nitrogen (N15) administered to animals gives rise to erythrocyte heme containing N15. With this observation as the foundation almost the entire biosynthetic pathway of heme has been elucidated. Rapid advances in this field followed quickly upon the finding by Shemin and his colleagues2 and by