Administration of biotin prevents the development of insulin resistance in the skeletal muscles of Otsuka Long-Evans Tokushima fatty rats.

摘要

Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for type 2 diabetes mellitus. Effects of pharmacologic doses of biotin on insulin resistance in skeletal muscles of OLETF rats were determined. OLETF rats (34 wk old) were divided into 2 groups and given distilled water (OLETF-control group) or distilled water containing 3.3 mg l--1 biotin (OLETF-biotin group) for 8 wk. At the end of the experimental period, OLETF-control rats developed severe hyperglycaemia and hyperinsulinaemia, whereas OLETF-biotin rats showed markedly smaller responses to oral glucose tolerance tests than OLETF-control rats. Glucose uptake in the hind limbs of rats was markedly higher in the OLETF-biotin group than in the OLETF-control group. Biotin administration increased glucose transporter type 4 (GLUT4) protein content in the total membrane fraction but had little effect on GLUT4 content in plasma membrane fraction. Results indicate that administration of a pharmacological dose of biotin prevents the development of insulin resistance in skeletal muscles of OLETF rats presumably via an increase in GLUT4 protein expression but not via GLUT4 translocation.