Chloramphenicol inhibits hemoglobin synthesis in blood islands of young chick blastoderm.

Hemoglobin (Hb) synthesis is reduced by 1.5 to 12.4 X 10(-4) M chloramphenicol (CAP) in chick blastoderms at head process and 4-somite stages. Chloramphenicol at 18.6 X 10(-4) M results in decrease of amino acid uptake and incorporation into protein, and inhibits Hb formation completely. However, this effect can be overcome partially when blastoderms are removed from CAP-containing to plain culture medium. The morphological appearance, protein content, and behaviour in amino acid uptake and incorporation of control and CAP-treated blastoderms at the time Hb first makes its appearance can be correlated and seem to reflect changes occurring in the vascular area during the time of blood island organization and subsequent massive Hb synthesis in the simple culture system employed.