HEMOGLOBIN C IN NEWBORN SHEEP AND GOATS - A POSSIBLE EXPLANATION FOR ITS FUNCTION AND BIOSYNTHESIS

Extract:Chromatographic analyses of the hemoglobins of newborn kids over a postnatal period of 120 to 140 days have shown that fetal hemoglobin is replaced by βC chain-containing hemoglobin types rather than by normal βA chain-containing adult hemoglobin components. These βC chain-containing hemoglobins are the same as those observed in adult goats subjected to severe blood-loss anemia. A similar, but quantitatively different, phenomenon was also observed in newborn lambs. The increase in βC chain production is preceded by an elevation of an erythropoietic stimulating factor (ESF) in blood plasma. When ESF extract of human urinary origin was injected into either young lambs or a young kid, an increased production of βC chain-containing hemoglobins was observed. Speculation:It is postulated that the production of βC chain-containing hemoglobin types in the newborn kid is a physiological adjustment that allows these fast growing animals to supply oxygen to the tissues in an easy fashion. The effects observed as a response to an increased ESF activity in serum are interpreted to be the result of two separate mechanisms that differ qualitatively and quantitatively. The low sensitivity of sheep to the stimulus of an elevated ESF activity is explained by a possible formation of an activator-inhibitor complex resulting in a decreased activation of the silent HbβC structural gene. © International Pediatrics Research Foundation, Inc. 1969. All Rights Reserved.