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Lipoic acid increases glucose uptake by skeletal muscles of obese‐diabetic ob/ob mice
Author(s) -
Eason R. C.,
Archer H. E.,
Akhtar S.,
Bailey C. J.
Publication year - 2002
Publication title -
diabetes, obesity and metabolism
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.445
H-Index - 128
eISSN - 1463-1326
pISSN - 1462-8902
DOI - 10.1046/j.1463-1326.2002.00171.x
Subject(s) - medicine , endocrinology , alpha lipoic acid , insulin , lipoic acid , glucose uptake , chemistry , skeletal muscle , biology , biochemistry , antioxidant , oxidative stress
Aim: Alpha‐lipoic acid has been reported to increase glucose disposal in diabetic states. This study has examined the effect of α‐lipoic acid on glucose uptake by cultured L6 muscle cells and different types of skeletal muscles in normal lean (+/+) and severely insulin‐resistant, obese‐diabetic ( ob/ob ) mice. Methods: Glucose uptake was measured in L6 muscle cells using the non‐metabolized glucose analogue 2‐deoxy‐ d ‐glucose (2DG), and in isolated muscles by glucose disappearance from the incubation medium. Results: In L6 muscle cells, short‐term incubations (2–12 h) with 10 −3 m α‐lipoic acid increased glucose uptake by 40–80%, approximately the same extent as 10 −6 m insulin. Combination of the two agents produced a slightly greater increase (120% at 12 h) than either alone. Red quadriceps (mainly type 1 fibres), diaphragm (similar proportions of type 1 and 2 fibres) and abdominal muscle (mainly type 2 fibres) from normal mice incubated with 10 −3 m α‐lipoic acid showed increased glucose uptake to a similar extent as 10 −6 m insulin in each of the three muscles. Muscles from ob/ob mice, which showed little response to insulin, showed a substantial increase (approximately 300%, p < 0.05–0.01) in glucose uptake when 10 −3 m α‐lipoic acid was added in the presence of insulin. The α‐lipoic acid also increased glucose uptake in red quadriceps (approximately 300%, p < 0.01) from ob/ob mice without added insulin. Conclusion: The results suggest that α‐lipoic acid can increase glucose uptake by a range of normal muscle types and improve the response to insulin by insulin‐resistant skeletal muscles of ob/ob mice.