Synthesis of hemoglobin chains in adult and newborn goats: possible influence of the beta c synthesis on the production of alpha chains.

Abstract

The rates of in vitro synthesis of hemoglobin alpha and non-alpha 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% beta C chain about 10 days after the start of the experiment. Severe anemia and the production of beta C chain was accompanied by a significant increase in the alpha/non-alpha synthesis ratio. The gamma chain production in the newborns declined rapidly after birth and was completely replaced by that of the beta C chain in 7-10 days. No significant difference in the relative synthesis of the three types of alpha chain was observed during this period. Goats with either a homozygosity for the I alpha or I alpha B chains synthesize the I alpha (or I alpha B) and II alpha chains at a ratio of 3:1. When a heterozygosity for I alpha B chains is present the I alpha:I alpha B:II alpha ratio approximates 2:1:1. Results of kinetic studies suggest that the II alpha chains are synthesized at a slower rate than the II alpha chains. The difference in the alpha/non-alpha ratio during severe anemia may be due to a decreased production of beta C chains. No significant difference in the relative synthesis of the I alpha, I alpha B, and II alpha chains was observed between the anemic adult animal and the newborn goat or the growing kid.