Muscle ubiquinone in male effort angina patients.

Seven (7) males with effort angina and listed for coronary by-pass surgery had muscle biopsies taken from their vastus lateralis muscle for determination of muscle fiber types (%ST), ubiquinone (vitamin Q, UQ), oxidative and fermentative enzyme activities. Graded cycle ergometer exercise to determine intensities corresponding to onset of blood lactate accumulation set to 2.0 mmol x l-1 (WOBLA) and symptom limited exercise ('maximal', WSL) were also undertaken. WOBLA was positively related to %ST (r = 0.92, p < 0.001). %ST was on the other hand inversely related to UQ (r = -0.82, p < 0.05), the heart specific LD subunit LD-H (r = -0.96, p < 0.001), the isozyme LD3 as the fraction of LD (%LD3) (r = -0.93, p < 0.01), and the CK isozyme CKMB as the fraction of CK (%CKMB) (r = -0.88, p < 0.05). It was suggested that muscle UQ depletion in the patients was related to molecular oxygen and free oxygen radical formation. The lack of antioxidants then caused a radical trauma specifically to the ST fiber and their mitochondria. This could be a cause and-effect explanation for the selective ST fiber downregulation in effort angina and heart failure in general.