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Relative alpha and beta chain synthesis in erythroid bursts derived from human bone marrow and peripheral blood are presented. The biosynthetic ratios obtained are compared with those of the reticulocytes. The data obtained cell culture are similar to the "in vivo" ones, showing and alpha/beta ratio of 1 in normal individuals and higher than 1 in beta thalassemic heterozygous. The use of erythroid cell culture as an experimental model for the study of differentiation at molecular level is therefore possible.

The intracellular behaviour of the excess newly synthesized α-globin has been studied by incubating peripheral blood and bone marrow samples from 9 homozygous β-thalassemic subjects with labeled amino acids. The globin chains present in the cytoplasm and in association with the stromal material have been separated by column chromatography, and the incorporation of radioactivity has been determined for each globin at various incubation times. The results obtained show that the excess of α-globin is removed from the cell cytoplasm and becomes associated with the stromal material. [ABSTRACT FROM AUTHOR]

Globin chain synthesis has been studied in β-thalassemia by incubating red blood cells of 10 homozygous thalassemic patients with [3H] amino acids, and by measuring the incorporation of radioactivity into the globin chains, separated by column chromatography. Five of the ten patients were never transfused, five were polytransfused. The following results were obtained: (a) absence of β chain synthesis in both polytransfused and never transfused patients; (b) excess of α chain synthesis in the ten cases examined (ratio α synthesis/(γ + δ) synthesis = 3.0). In three heterozygous subjects β globin synthesis and an excess of α chain synthesis was observed (ration α/(β + γ + δ) = 1.6). The possible interpretations of these results are presented in the discussion. [ABSTRACT FROM AUTHOR]