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Developmental changes in heart and muscle phosphofructokinase isozymes
The Journal of Biological Chemistry
|August 10, 1981
Summary
Phosphofructokinase (PFK) isozyme composition in rat heart and skeletal muscle changes significantly during development. Adult skeletal muscle primarily expresses PFK-M, while fetal and neonatal stages show a mix of PFK-M and PFK-L2.
Area of Science:
- Biochemistry
- Developmental Biology
- Enzymology
Background:
- Phosphofructokinase (PFK) is a key regulatory enzyme in glycolysis.
- Isozyme composition of PFK varies across tissues and developmental stages.
- Understanding these variations is crucial for metabolic regulation studies.
Purpose of the Study:
- To characterize phosphofructokinase (PFK) isozymes in fetal, neonatal, and adult rat heart and skeletal muscle.
- To investigate the developmental regulation of PFK isozyme expression.
- To compare PFK isozyme profiles between cardiac and skeletal muscle during development.
Main Methods:
- DEAE-cellulose chromatography for isozyme separation and quantification.
- Agarose gel electrophoresis for isozyme analysis.
- Immunodiffusion using specific antisera for isozyme identification.
Main Results:
- Skeletal muscle: Fetal and neonatal stages contain both PFK-M and PFK-L2. Adult skeletal muscle predominantly expresses PFK-M, with PFK-L2 becoming undetectable.
- Heart muscle: Fetal heart shows PFK-L2 as the major isozyme, with another distinct isozyme present. Neonatal and adult hearts express both PFK-M and PFK-L2, with PFK-M levels increasing postnatally.
- Quantitative analysis revealed significant shifts in the relative abundance of PFK-L2 and PFK-M during development in both tissue types.
Conclusions:
- PFK isozyme profiles in rat heart and skeletal muscle are developmentally regulated.
- The transition from fetal to adult PFK expression patterns reflects metabolic adaptation.
- Distinct developmental trajectories of PFK isozymes in heart versus skeletal muscle highlight tissue-specific metabolic needs.
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