title: Role of FAT/CD36 in novel PKC isoform activation in heart of spontaneously hypertensive rats.
abstract: Disruption to the sensitive balance of long-chain fatty acids and glucose in the heart could cause cardiovascular diseases. Searching for a possible role of novel protein kinase C (nPKC) in heart with disrupted energy balance, we compared the insulin-resistant spontaneously hypertensive rats (SHR), which carry a nonfunctional variant of the fatty acid transporter FAT/CD36, with the less insulin-resistant congenic strain SHR-4 that is genetically identical except for a segment on chromosome 4 including a wild-type gene for a functional FAT/CD36. We analyzed expression of the nPKC-δ and -ε isoforms plus triacylglycerols (TAG) content in the myocardium of both FAT/CD36 strains and after a high sucrose diet (HSD). Two weeks before killing, males of both strains were randomly divided into two groups and fed either a standard laboratory chow or an HSD. PKC was determined by Western blotting in particulate and cytosolic fractions from left ventricles. The SHR-4 rats exhibited lower serum levels of insulin and free fatty acids than did SHR rats and higher amounts of PKC-ε in the heart particulate fraction. HSD caused accumulation of heart TAG in SHR but not in SHR-4. HSD increased PKC-δ and decreased PKC-ε expression in particulate fraction from left ventricles of SHR-4 while having no effects in SHR. These results demonstrate that reduced insulin resistance in SHR-4 rats with wild-type FAT/CD36 is associated with the insulin signaling pathway involving nPKCs.
authors.affiliation: Department of Cell Biology, Charles University, Vinicna 7, 12843 Prague, Czech Republic.
authors.forename: Martina J
authors.initials: MJ
authors.lastname: Klevstig
authors.forename: Irena
authors.initials: I
authors.lastname: Markova
authors.forename: Jana
authors.initials: J
authors.lastname: Burianova
authors.forename: Ludmila
authors.initials: L
authors.lastname: Kazdova
authors.forename: Michal
authors.initials: M
authors.lastname: Pravenec
authors.forename: Olga
authors.initials: O
authors.lastname: Novakova
authors.forename: Frantisek
authors.initials: F
authors.lastname: Novak
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism; D018955:CD36 Antigens / Q000235:genetics / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004789:Enzyme Activation; D005230:Fatty Acids, Nonesterified / Q000097:blood / Q000378:metabolism; D005786:Gene Expression Regulation; D006352:Heart Ventricles / Q000378:metabolism*; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007333:Insulin Resistance / Q000235:genetics* / Q000502:physiology; D008297:Male; D009206:Myocardium / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000096:biosynthesis*; D051744:Protein Kinase C-epsilon / Q000096:biosynthesis*; D051381:Rats; D011918:Rats, Inbred SHR; D015398:Signal Transduction; D013395:Sucrose / Q000378:metabolism; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D018955:CD36 Antigens; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D014280:Triglycerides; D013395:Sucrose; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon