Decreased protein kinase C-epsilon expression in hypertrophied cardiac ventricles induced by triiodothyronine treatment in the rat.
To examine the effect of thyroid hormone-induced cardiac hypertrophy on PKC expression, changes in the expression of PKC isoforms were studied in hypertrophied cardiac ventricles induced by triiodothyronine (T3) injection in the rat. Injection with T3 for 8 days induced 49% increase in cardiac weight compared to controls. Immunoblot analysis of cardiac ventricular extracts showed the expression of PKC-delta, -epsilon, and -zeta in both control and T3-treated groups. The expression of PKC-epsilon decreased by 40% in hyperthyroid rat cardiac ventricles, while PKC-delta and -zeta expressions were barely affected. PKC-epsilon immunoreactivity decreased in both cytosol and membrane fractions. On the contrary, PKC-epsilon expression did not decrease in the extract of hypertrophied cardiac ventricles produced by aortic banding or aortocaval shunt. These results indicate that thyroid hormone down regulates PKC-epsilon expression in the hyperthyroid-mediated cardiac hypertrophy.
Hamasaki
Y
Y
Department of Pediatrics, Tokai University School of Medicine, Kanagawa-ken, Japan.
Shinohara
O
O
Ishida
H
H
Hayashi
Y
Y
Nakazawa
H
H
D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D001166:Arteriovenous Shunt, Surgical; D002118:Calcium / Q000378:metabolism; D004195:Disease Models, Animal; D006352:Heart Ventricles / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D017379:Hypertrophy, Left Ventricular / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology; D017380:Hypertrophy, Right Ventricular / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology; D007279:Injections, Subcutaneous; D007527:Isoenzymes / Q000378:metabolism*; D008026:Ligation; D008297:Male; D009206:Myocardium / Q000166:cytology / Q000201:enzymology; D009929:Organ Size / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism*; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; D051381:Rats; D017207:Rats, Sprague-Dawley; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D014284:Triiodothyronine / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D000099221:Protein Kinase C zeta
D002118:Calcium; D007527:Isoenzymes; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; D014284:Triiodothyronine; D000099221:Protein Kinase C zeta; C497260:Prkcd protein, rat; C497257:Prkce protein, rat