Synthesis of Hemoglobin chains in Adult and Newborn Goats: Possible Influence of the β^c Synthesis on the Production of α CHAINS

Abstract

The rates of in vitro synthesis of hemoglobin a and non-a chains were determined in adult goats during blood loss anemia and in newborn goats during postnatal development. the reticulocytes were incubated in a medium supporting protein synthesis and containing [¹⁴C] leucine. the hemoglobin chains were separated by CM-cellulose chromatography. the adult animals responded to the phlebotomy with a production of nearly 100% β^c chain about 10 days after the start of the experiment. Severe anemia and the production of β^C chain was accompanied by a significant increase in the α/non-α-synthesis ratio. the y chain production in the newborns declined rapidly after birth and was completely replaced by that of the β^c chain in 7-10 days. No significant difference in the relative synthesis of the three types of α chain was observed during this period. Goats with either a homozygosity for the I_α or I_α-chains synthesize the I_α (or I_β) and II_α chains at a ratio of 3:1. When a heterozygosity for I_αB chains is present the Iα:IαB:IIα ratio approximates 2:1:1. Results of kinetic studies suggest that the IIα chains are synthesized at a slower rate than the I_αor I_αβ chains. the difference in the α/non-α ratio during severe anemia may be due to a decreased production of β^c chains. No significant difference in the relative synthesis of the Iα, I_αβ, II_α chains was observed between the anemic adult animal and the newborn goat or the growing kid.