Mitochondrial function in heart muscle from patients with idiopathic dilated cardiomyopathy.
OBJECTIVE
To study the mitochondrial respiratory chain enzyme activities in patients with idiopathic dilated cardiomyopathy (IDC).


METHODS
Mitochondrial respiratory chain enzyme activities were assessed spectrophotometrically in left ventricular tissue of 17 patients with IDC undergoing cardiac transplantation, as well as in two groups of controls: a group of six patients suffering from ischemic dilated cardiomyopathy (IC) also undergoing cardiac transplantation, and a group of 17 organ donors considered normal from a cardiac point of view. Cytochrome b gene from three IDC patients whose complex III activity was particularly low and from three controls was also sequenced.


RESULTS
We found that complex III enzymatic activity was lower not only in IDC but also in IC patients when compared with normal controls. When analysing cytochrome b gene we only found neutral polymorphisms previously described.


CONCLUSIONS
In view of such results, we believe that the decrease of respiratory chain complex III activity found in some cases of IDC is a secondary phenomenon, and not due to a primary mitochondrial disease.
Jarreta
D
D
Departament de Medicina, Hospital Clinic i Provincial, IDIBAPS, Facultat de Medicina, UB, Spain.
Orús
J
J
Barrientos
A
A
Miró
O
O
Roig
E
E
Heras
M
M
Moraes
C T
CT
Cardellach
F
F
Casademont
J
J
D000328:Adult; D000704:Analysis of Variance; D002311:Cardiomyopathy, Dilated / Q000209:etiology / Q000378:metabolism*; D016022:Case-Control Studies; D002950:Citrate (si)-Synthase / Q000032:analysis; D003573:Cytochrome b Group / Q000235:genetics; D004579:Electron Transport; D042967:Electron Transport Complex I; D042963:Electron Transport Complex II; D014450:Electron Transport Complex III / Q000032:analysis; D003576:Electron Transport Complex IV / Q000032:analysis; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008929:Mitochondria, Heart / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000032:analysis; D017202:Myocardial Ischemia / Q000150:complications / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000032:analysis; D010085:Oxidative Phosphorylation; D010088:Oxidoreductases / Q000032:analysis; D017422:Sequence Analysis, DNA; D013053:Spectrophotometry; D013385:Succinate Dehydrogenase / Q000032:analysis
D003573:Cytochrome b Group; D009097:Multienzyme Complexes; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D009247:NADH, NADPH Oxidoreductases; D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III