A high-capacity assay for activators of glucose incorporation into glycogen in L6 muscle cells.
Skeletal muscle is the major tissue responsible for insulin-stimulated glucose uptake and incorporation into glycogen. Skeletal muscle insulin resistance and the resulting postprandial hyperglycemia are hallmarks of non-insulin-dependent diabetes. Therefore, compounds that serve as insulin mimetics or insulin sensitizers in skeletal muscle may be effective in the treatment of diabetes. In order to identify such hypoglycemic agents, a novel assay for activators of glucose incorporation into glycogen has been developed utilizing differentiated L6 muscle cells in 96-well plates. We found that glucose incorporation occurs in a time- and concentration-dependent manner. It is inhibitable by phloretin, an inhibitor of glucose transport. Both insulin and the insulin-mimetic compound pervanadate activate L6 cell glucose incorporation in dose-responsive manners. We conclude that this assay should serve as a high-capacity screen to identify novel compounds that upregulate glucose anabolic metabolism in skeletal muscle. Such chemical entities may prove useful as antidiabetic agents.
Department of Molecular Endocrinology, Merck Research Laboratories, Rahway, New Jersey, 07065, USA. Joel_Berger@Merck.com
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D000818:Animals; D002460:Cell Line; D005947:Glucose / Q000378:metabolism*; D006003:Glycogen / Q000096:biosynthesis / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000737:chemistry / Q000494:pharmacology; D018716:Molecular Mimicry; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D051381:Rats
D007004:Hypoglycemic Agents; D007328:Insulin; D006003:Glycogen; D005947:Glucose