TY - JOUR
T1 - Different respiratory activities of mitochondria isolated from the subendocardium and subepicardium of the canine heart
AU - Camici, P.
AU - Ursini, F.
AU - Galiazzo, F.
AU - Bellitto, L.
AU - Pelosi, G.
AU - Marzilli, M.
AU - L'Abbate, A.
AU - Barsacchi, R.
PY - 1984/7
Y1 - 1984/7
N2 - Mitochondria were prepared from the subendocardial and subepicardial layers of the canine left ventricle. The oxidation rates of palmitate, palmitoyl carnitine and pyruvate of the mitochondria obtained from the two cardiac layers were measured. The cytochrome content and the specific activities of different beta oxidation and Krebs cycle enzymes were also measured in the two mitochondrial populations. Mitochondria isolated from the ENDO layer showed significantly higher oxidation rates than mitochondria from the EPI layer for all the three substrates. No statistically significant differences in cytochrome c+c1 and a+a3 content were found in mitochondria isolated from the two regions. No significant transmural differences were found in fatty acyl CoA, L-3-hydroxy fatty acyl CoA, succinic and malic dehydrogenase specific activities, whilst isocitric dehydrogenase (NADP) specific activity was significantly higher in mitochondria isolated from the inner layer. In conclusion, the mitochondria isolated from the inner left ventricular layer of the canine heart show a higher oxidative capacity than subepicardial mitochondria. This difference could partly be explained by the higher specific activity of isocitric dehydrogenase in this layer. These properties of subendocardial mitochondria could represent a metabolic support for the greater contractile performance of this layer.
AB - Mitochondria were prepared from the subendocardial and subepicardial layers of the canine left ventricle. The oxidation rates of palmitate, palmitoyl carnitine and pyruvate of the mitochondria obtained from the two cardiac layers were measured. The cytochrome content and the specific activities of different beta oxidation and Krebs cycle enzymes were also measured in the two mitochondrial populations. Mitochondria isolated from the ENDO layer showed significantly higher oxidation rates than mitochondria from the EPI layer for all the three substrates. No statistically significant differences in cytochrome c+c1 and a+a3 content were found in mitochondria isolated from the two regions. No significant transmural differences were found in fatty acyl CoA, L-3-hydroxy fatty acyl CoA, succinic and malic dehydrogenase specific activities, whilst isocitric dehydrogenase (NADP) specific activity was significantly higher in mitochondria isolated from the inner layer. In conclusion, the mitochondria isolated from the inner left ventricular layer of the canine heart show a higher oxidative capacity than subepicardial mitochondria. This difference could partly be explained by the higher specific activity of isocitric dehydrogenase in this layer. These properties of subendocardial mitochondria could represent a metabolic support for the greater contractile performance of this layer.
KW - beta-oxidation enzymes
KW - Krebs cycle enzymes
KW - myocardial mitochondria
KW - palmitic acid oxidation rate
KW - pyruvic acid oxidation rate
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U2 - 10.1007/BF01908146
DO - 10.1007/BF01908146
M3 - Article
C2 - 6487238
AN - SCOPUS:0021185073
VL - 79
SP - 454
EP - 460
JO - Basic Research in Cardiology
JF - Basic Research in Cardiology
SN - 0300-8428
IS - 4
ER -