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The Effect of Lead on Total Globin and a‐ and P‐Chain Synthesis; in Vitro and in Vivo

Summary. The effect of lead in vitro and in viuo on the synthesis of total globin and a and fl chains in reticulocytes has been studied. In vitro lead at concentrations of 50–400 μg/dl of whole blood was shown to depress globin synthesis; the degree of depression being dependent on the concentration. Also a‐chain synthesis was inhibited more than β‐chain synthesis. Part of these effects could be explained by the fact that lead inhibited the incorporation of [3H]leucine into the reticulocytes. Haemin added to the incubation mixture prior to the addition of lead corrected the inhibition of total globin synthesis, but only partially corrected the imbalance of α‐ and β‐chain synthesis. Studies on the distribution of 203Pb within the red cell showed that it rapidly became bound to red‐cell stroma, ribosomes and haemglobin. In vivo it was found that in 28 lead workers there was no significant alteration in the synthesis of a and β chains when compared with normal controls. However, in six of the lead workers, the α/β ratio was greater than 1.2. The results are discussed in terms of the effect of lead upon haemoglobin synthesis.