SKELETAL-MUSCLE AND LIVER LIPOYLLYSINE CONTENT IN RESPONSE TO EXERCISE, TRAINING AND DIETARY ALPHA-LIPOIC ACID SUPPLEMENTATION

In human cells, alpha-lipoic acid (LA) is present in a bound lipoyllys ine form in mitochondrial proteins that play a central role in oxidati ve metabolism. The possible effects of oral LA supplementation, a sing le bout of strenuous exercise and endurance exercise training on the l ipoyllysine content in skeletal muscle and liver tissues of rat were e xamined. Incorporation of lipoyl moiety to tissue protein was not incr eased by enhanced abundance of LA in the diet. Endurance exercise trai ning markedly increased lipoyllysine content in the liver at rest. A b out of exhaustive exercise also increased hepatic lipoyllysine content . A significant interaction of exhaustive exercise and training to inc rease tissue lipoyllysine content was evident. In vastus lateralis ske letal muscle, training did not influence tissue lipoyllysine content. A single bout of exhaustive exercise, however, clearly increased the l evel of lipoyllysine in the muscle. Comparison of tissue lipoyllysine data with that of free or loosely-bound LA results showed a clear lack of association between the two apparently related parameters. Tightly protein-bound lipoyllysine pool in tissues appeared to be independent of the loosely-bound or free LA status in the tissue.