Protein kinase C activity and isoform expression during early postnatal development of rat myocardium.

摘要: Total protein kinase C (PKC) activity, its isoform expression, and concentration fatty acid (FA) composition of diacylglycerol (DAG) were determined in the left ventricular myocardium rat during early postnatal development (d 2, 3, 5, 7, 10). PKC activity measured by incorporation 32P into histone IIIS decreased between d 2 10 homogenate as well cytosolic, membrane (100,000g), nuclear-cytoskeletal-myofilament fractions (1000g). Likewise, expression isoforms (α, δ, e) immunoblotting generally declined period analyzed, although with a variable pattern. In nuclear cytoskeletal myofilament fractions, PKCδ PKCe markedly returning to or close level immediately on 5. PKCα fraction remained almost unchanged declining thereafter. associated predominantly particulate whereas was more abundant cytosolic fraction. DAG exhibited significant decline consistent decrease maximal activity. The unsaturation index FA tended 3 owing lowered proportion all polyunsaturated n−6 n−3 series. These results demonstrate that developmental is not linear subcellular localization enzyme exhibits isoform-specific day-by-day changes period. are compatible view signaling may be involved control rapid switch myocardial growth pattern first week life.