BACKGROUND: Myocardial protection by anesthetics is known to involve activation of protein kinase C (PKC). The authors' objective was to identify the PKC isoforms activated by propofol in rat ventricular myocytes. They also assessed the intracellular location of individual PKC isoforms before and after treatment with propofol. METHODS: Freshly isolated ventricular myocytes were obtained from adult rat hearts. Immunoblot analysis of cardiomyocyte subcellular fractions was used to assess translocation of individual PKC isoforms before and after exposure to propofol. An enzyme-linked immunosorbent assay kit was used for measuring PKC activity. Immunocytochemistry and confocal microscopy were used to visualize the intracellular location of the individual PKC isoforms. RESULTS: Under baseline conditions, PKC-alpha, PKC-delta, and PKC-zeta were associated with both the cytosolic and membrane fractions, whereas PKC-epsilon was exclusively located in the cytosolic fraction. Propofol (10 microM) caused translocation of PKC-alpha, PKC-delta, PKC-epsilon, and PKC-zeta from cytosolic to membrane fraction and increased total PKC activity (211 +/- 17% of baseline; P = 0.003) in a dose-dependent manner. Immunocytochemical localization of the individual PKC isoforms demonstrated that propofol caused translocation of PKC-alpha to the intercalated discs and z-lines; PKC-delta to the perinuclear region; PKC-epsilon to sites associated with the z-lines, intercalated discs, and the sarcolemma; and PKC-zeta to the nucleus. CONCLUSIONS: These results demonstrate that propofol causes an increase in PKC activity in rat ventricular myocytes. Propofol stimulates translocation of PKC-alpha, PKC-delta, PKC-epsilon, and PKC-zeta to distinct intracellular sites in cardiomyocytes. This may be a fundamentally important cellular mechanism of anesthesia-induced myocardial protection in the setting of ischemia-reperfusion injury.
BACKGROUND: Myocardial protection by anesthetics is known to involve activation of protein kinase C (PKC). The authors' objective was to identify the PKC isoforms activated by propofol in rat ventricular myocytes. They also assessed the intracellular location of individual PKC isoforms before and after treatment with propofol. METHODS: Freshly isolated ventricular myocytes were obtained from adult rat hearts. Immunoblot analysis of cardiomyocyte subcellular fractions was used to assess translocation of individual PKC isoforms before and after exposure to propofol. An enzyme-linked immunosorbent assay kit was used for measuring PKC activity. Immunocytochemistry and confocal microscopy were used to visualize the intracellular location of the individual PKC isoforms. RESULTS: Under baseline conditions, PKC-alpha, PKC-delta, and PKC-zeta were associated with both the cytosolic and membrane fractions, whereas PKC-epsilon was exclusively located in the cytosolic fraction. Propofol (10 microM) caused translocation of PKC-alpha, PKC-delta, PKC-epsilon, and PKC-zeta from cytosolic to membrane fraction and increased total PKC activity (211 +/- 17% of baseline; P = 0.003) in a dose-dependent manner. Immunocytochemical localization of the individual PKC isoforms demonstrated that propofol caused translocation of PKC-alpha to the intercalated discs and z-lines; PKC-delta to the perinuclear region; PKC-epsilon to sites associated with the z-lines, intercalated discs, and the sarcolemma; and PKC-zeta to the nucleus. CONCLUSIONS: These results demonstrate that propofol causes an increase in PKC activity in rat ventricular myocytes. Propofol stimulates translocation of PKC-alpha, PKC-delta, PKC-epsilon, and PKC-zeta to distinct intracellular sites in cardiomyocytes. This may be a fundamentally important cellular mechanism of anesthesia-induced myocardial protection in the setting of ischemia-reperfusion injury.
Authors: Peter J Wickley; Ryo Yuge; Mary S Russell; Hongyu Zhang; Michael A Sulak; Derek S Damron Journal: Anesthesiology Date: 2010-10 Impact factor: 7.892
Authors: Gaynor Aguilar; Francisco Córdova; Tania Koning; José Sarmiento; Mauricio P Boric; Konstantin Birukov; Jorge Cancino; Manuel Varas-Godoy; Andrea Soza; Natascha G Alves; Patricio E Mujica; Walter N Durán; Pamela Ehrenfeld; Fabiola A Sánchez Journal: Am J Physiol Heart Circ Physiol Date: 2021-10-15 Impact factor: 4.733
Authors: Janet R Manning; Sarah O Perkins; Elizabeth A Sinclair; Xiaoqian Gao; Yu Zhang; Gilbert Newman; W Glen Pyle; Jo El J Schultz Journal: Am J Physiol Heart Circ Physiol Date: 2013-03-11 Impact factor: 4.733