Journal of Lipid Research (Sep 1999)
Microanalysis of cardiolipin in small biopsies including skeletal muscle from patients with mitochondrial disease
Abstract
Cardiolipin is a specific mitochondrial phospholipid that is present in mammalian tissues in low concentration. To measure cardiolipin in small biopsies from patients with mitochondrial disease, we developed a new technique that can detect subnanomolar levels of well-resolved molecular species, the most abundant of which are tetralinoleoylcardiolipin (L4) and trilinoleoyl-oleoyl-cardiolipin (L3O). To this end, a fluorescence-labeled derivative of cardiolipin (2-[naphthyl-1′-acetyl]-cardiolipin dimethyl ester) was formed and analyzed by high performance liquid chromatography. Cardiolipin was measured in skeletal muscle biopsies from 8 patients with mitochondrial disease and in 17 control subjects. In 5 patients with mitochondrial disease, cardiolipin content was higher than normal (2.4–7.0 vs. 0.4–2.2 nmol/mg protein). In 3 patients with mitochondrial disease, the L4/L3O ratio was lower than normal (2–4 vs. 4–6). Cardiolipin was also measured in various rat and dog muscle tissues. The L4/L3O ratio was higher in condensed “muscle” type mitochondria (heart ventricle, skeletal muscle, ratios 4–7) than in orthodox “liver” type mitochondria (liver, smooth muscle, heart auricular appendage, H9c2 myoblasts, ratios 0.4–3), suggesting that the L4/L3O proportion is important for cristae membrane structure. We concluded that the L4/L3O ratio is a tissue-specific variable that may change in the presence of mitochondrial disease. The new method is suitable to measure cardiolipin in muscle biopsies in order to estimate concentration of mitochondria.—Schlame, M., S. Shanske, S. Doty, T. König, T. Sculco, S. DiMauro, and T. J. J. Blanck. Microanalysis of cardiolipin is small biopsies including skeletal muscle from patients with mitochondrial disease. J. Lipid Res. 1999. 40: 1585–1592.
