Thyroid hormone augments GLUT4 expression and insulin-sensitive glucose transport system in differentiating rat brown adipocytes in culture

• Published in: Journal of Veterinary Medical Science Vol. 64; no. 8; pp. 677 - 681
• Main Authors: "Shimizu, Y. (Ehime Univ., Shigenobu (Japan). School of Medicine), Shimazu, T.
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 01.08.2002; Japan Science and Technology Agency
• Subjects: Adipocytes - drug effects; Adipocytes - metabolism; Adipose Tissue, Brown - cytology; Animals; Blotting, Western; Cell Differentiation; Cells, Cultured; Dose-Response Relationship, Drug; Glucose - metabolism; Glucose Transporter Type 1; Glucose Transporter Type 4; GLUT; INSULIN; Insulin - metabolism; Monosaccharide Transport Proteins - drug effects; Monosaccharide Transport Proteins - metabolism; Muscle Proteins; NOREPINEPHRINE; Norepinephrine - metabolism; rat brown adipocyte; RATS; THYROID HORMONES; Triiodothyronine - pharmacology
• ISSN: 0916-7250; 1347-7439; 1347-7439
• DOI: 10.1292/jvms.64.677

"The effects of triiodothyronine (T3) on differentiation-dependent expression of GLUT and responses of glucose transport to insulin and norepinephrine (NE) were investigated. Precursor -cells of brown adipocytes isolated from the interscapular brown adipose tissue of newborn rats were cultured in the absence or presence of various concentrations of T3. Western bolt analysis revealed that treatment with T3 resulted in an increased expression of GLUT4, in a dose-dependent manner, whereas GLUTL contents were unchanged. In parallel with the increase in GLUT4 expression, T3 improved insulin sensitivity for glucose transport, being accompanied by an increase in maximal transport rate and a reduction of ED sub50. In contrast, T3-treatment of the brown adipocytes during the differentiation process had little effect on NE-regulatable glucose transport system. These results suggest that T3 plays a predominant role in the development of insulin-sensitive glucose transport during differentiation of brown adipocytes."