Postnatal changes in canine erythrocyte pyruvate kinase isozymes

✍ Scribed by Paul A. Mueggler; Sarah Carpenter; John A. Black

• Publisher: Springer
• Year: 1983
• Tongue: English
• Weight: 640 KB
• Volume: 21
• Category: Article
• ISSN: 0006-2928
• DOI: 10.1007/bf00498916

✦ Synopsis

The isozyme pattern of pyruvate kinase in canine erythrocytes changes following birth. These changes have been followed by electrophoretic, immunologic, and kinetic measurements of the isozymes. At birth, a mixture of isozymes is present consisting of the M 2 isozyme and hybrid molecules containing M 2 and R subunits. With increasing animal age, the content of M2 subunits decreases and the content of R subunits increases. At 6 months of age, the isozyme pattern is indistinguishable from that of adult erythrocytes which contain only the R tetramer. We conclude that there is a switch in erythrocyte pyruvate kinase gene expression during the first 6 months of postnatal life. The existence of hybrid molecules during the switch indicates that both M2 and R genes are expressed within each erythroid precursor cell. The developmental changes in erythrocyte pyruvate kinase are consistent with the role of this enzyme in the regulation of the oxygen-transport function of canine hemoglobin by 2,3-diphosphoglycerate in the postnatal period.