alpha-Lipoic acid increases cardiac glucose oxidation independent of AMP-activated protein kinase in isolated working rat hearts

BEŞİKCİ A., Wagg C., Lopaschuk T. P., Keung W., Lopaschuk G. D.

BASIC RESEARCH IN CARDIOLOGY, cilt.102, sa.5, ss.436-444, 2007 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 102 Sayı: 5
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1007/s00395-007-0661-4
  • Dergi Adı: BASIC RESEARCH IN CARDIOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.436-444
  • Anahtar Kelimeler: glucose oxidation, AMP-activated protein kinase, AKT, lipotoxicity, ACETYL-COA CARBOXYLASE, SKELETAL-MUSCLE, THIOCTIC ACID, MALONYL-COA, 3T3-L1 ADIPOCYTES, STIMULATION, ANTIOXIDANT, TRANSPORT, TRANSLOCATION, REPERFUSION
  • Ankara Üniversitesi Adresli: Evet

Özet

alpha- Lipoic acid ( ALA) is a naturally occurring enantiomer of lipoic acid and is a cofactor of key metabolic enzyme complexes catalyzing the decarboxylation of alpha- keto acids. It was recently shown that ALA increases insulin sensitivity by activating AMP- activated protein kinase ( AMPK) in skeletal muscle. Also, administration of ALA to obese rats increases insulin- stimulated glucose uptake in the whole body. We investigated the metabolic effects of ALA on isolated working rat hearts. ALA ( 500 mu M) stimulated glucose oxidation ( 157 +/- 31 nmol center dot dry wt(-1) center dot min(-1) in control vs 315 +/- 63 nmol center dot dry wt (-1) center dot min (- 1) in ALA- treated, p < 0.05) without affecting glycolysis, lactate oxidation, or palmitate oxidation. Cardiac work was not affected by ALA treatment. The effect of ALA on glucose oxidation was not associated with an activation of AMPK. AMPK activity was 190 +/- 14 pmol center dot mg protein(-1) center dot min(-1) in control vs 190 +/- 16 pmol center dot mg protein(-1) center dot min(-1) in ALA-treated hearts. This study shows that ALA stimulates glucose oxidation in isolated working rat hearts independent of AMPK activation. The beneficial effects of ALA treatment in diabetic patients may be at least in part related to its effect on glucose metabolism.