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Updated: Aug 16, 2026
Analysis of Cardiomyocyte Development using Immunofluorescence in Embryonic Mouse Heart
Published on: March 26, 2015
Protein kinase C activity and isoform expression during early postnatal development of rat myocardium
B Hamplova1, O Novakova, E Tvrzicka
1Department of Animal Physiology, Faculty of Science, Charles University in Prague, Vinicna 7, 128 44 Prague 2, Czech Republic.
Insights
Protein kinase C (PKC) activity and expression decrease in rat heart during early development. Changes in PKC isoforms and diacylglycerol fatty acid composition suggest a role in regulating myocardial growth patterns.
Area of Science:
- Cardiovascular Physiology
- Molecular Biology
- Developmental Biology
Background:
- Protein kinase C (PKC) plays a crucial role in cellular signaling pathways.
- Understanding PKC's role in myocardial development is essential for comprehending cardiac growth regulation.
Purpose of the Study:
- To investigate the developmental changes in total PKC activity, isoform expression, and diacylglycerol (DAG) fatty acid composition in rat left ventricular myocardium.
- To correlate these changes with early postnatal cardiac development.
Main Methods:
- Quantification of total PKC activity via 32P incorporation into histone IIIS.
- Determination of PKC isoform (alpha, delta, epsilon) expression using immunoblotting.
- Analysis of DAG concentration and fatty acid composition.
Main Results:
- Total PKC activity and expression of PKC isoforms (alpha, delta, epsilon) generally declined from postnatal day 2 to 10.
- PKC isoform expression and subcellular localization showed dynamic, isoform-specific changes.
- DAG concentration decreased by day 5, correlating with reduced PKC activity.
Conclusions:
- The developmental decrease in rat myocardial PKC activity and expression is non-linear and isoform-specific.
- Dynamic changes in PKC subcellular localization and DAG composition suggest a role in regulating early myocardial growth patterns.
Abstract:
Total protein kinase C (PKC) activity, its isoform expression, and concentration and fatty acid (FA) composition of diacylglycerol (DAG) were determined in the left ventricular myocardium of the rat during early postnatal development (d 2, 3, 5, 7, and 10). PKC activity measured by the incorporation of 32P into histone IIIS decreased between d 2 and 10 in the homogenate as well as in cytosolic, membrane (100,000 g), and nuclear-cytoskeletal-myofilament fractions (1000 g). Likewise, the expression of PKC isoforms (alpha, delta, and epsilon) determined by immunoblotting generally declined during the period analyzed, although with a variable pattern. In the membrane and nuclear cytoskeletal myofilament fractions, PKCdelta and PKCepsilon expression decreased markedly by d 3, returning to or close to the d 2 level immediately on d 5. PKCalpha expression in the membrane fraction remained almost unchanged by d 7, declining thereafter. PKCdelta and PKCepsilon were associated predominantly with particulate fractions, whereas PKCalpha was more abundant in the cytosolic fraction. DAG concentration exhibited a significant decline by d 5, consistent with the decrease in maximal PKC activity. The unsaturation index of FA in DAG tended to decrease on d 3 owing to the lowered proportion of all polyunsaturated FA of n-6 and n-3 series. These results demonstrate that the developmental decrease in PKC activity and expression in the rat myocardium is not linear and that subcellular localization of the enzyme exhibits isoform-specific day-by-day changes during the early postnatal period. These changes are compatible with the view that PKC signaling may be involved in the control of a rapid switch of myocardial growth pattern during the first week of life.
