title: Soybean and sunflower oil-induced insulin resistance correlates with impaired GLUT4 protein expression and translocation specifically in white adipose tissue.
abstract: Free fatty acids are known for playing a crucial role in the development of insulin resistance. High fat intake is known for impairing insulin sensitivity; however, the effect of vegetable-oil injections have never been investigated. The present study investigated the effects of daily subcutaneous injections (100 microL) of soybean (SB) and sunflower (SF) oils, during 7 days. Both treated groups developed insulin resistance as assessed by insulin tolerance test. The mechanism underlying the SB- and SF-induced insulin resistance was shown to involve GLUT4. In SB- and SF-treated animals, the GLUT4 protein expression was reduced approximately 20% and 10 min after an acute in vivo stimulus with insulin, the plasma membrane GLUT4 content was approximately 60% lower in white adipose tissue (WAT). No effects were observed in skeletal muscle. Additionally, both oil treatments increased mainly the content of palmitic acid ( approximately 150%) in WAT, which can contribute to explain the GLUT4 regulations. Altogether, the present study collects evidence that those oil treatments might generate insulin resistance by targeting GLUT4 expression and translocation specifically in WAT. These alterations are likely to be caused due to the specific local increase in saturated fatty acids that occurred as a consequence of oil daily injections.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Brazil.
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Poletto
authors.forename: Gabriel Forato
authors.initials: GF
authors.lastname: Anhê
authors.forename: Paula
authors.initials: P
authors.lastname: Eichler
authors.forename: Hilton Kenji
authors.initials: HK
authors.lastname: Takahashi
authors.forename: Daniela Tomie
authors.initials: DT
authors.lastname: Furuya
authors.forename: Maristela Mitiko
authors.initials: MM
authors.lastname: Okamoto
authors.forename: Rui
authors.initials: R
authors.lastname: Curi
authors.forename: Ubiratan Fabres
authors.initials: UF
authors.lastname: Machado
mesh_terms: D052436:Adipose Tissue, White / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000139:chemically induced / Q000378:metabolism*; D005227:Fatty Acids / Q000097:blood; D051275:Glucose Transporter Type 4 / Q000378:metabolism*; D007279:Injections, Subcutaneous; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D010938:Plant Oils / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D013024:Soybean Oil / Q000633:toxicity; D000074242:Sunflower Oil
chemical_list: D005227:Fatty Acids; D051275:Glucose Transporter Type 4; D007328:Insulin; D010938:Plant Oils; D000074242:Sunflower Oil; D013024:Soybean Oil