title: Circulating insulin stimulates fatty acid retention in white adipose tissue via KATP channel activation in the central nervous system only in insulin-sensitive mice.
abstract: Insulin signaling in the central nervous system (CNS) is required for the inhibitory effect of insulin on glucose production. Our aim was to determine whether the CNS is also involved in the stimulatory effect of circulating insulin on the tissue-specific retention of fatty acid (FA) from plasma. In wild-type mice, hyperinsulinemic-euglycemic clamp conditions stimulated the retention of both plasma triglyceride-derived FA and plasma albumin-bound FA in the various white adipose tissues (WAT) but not in other tissues, including brown adipose tissue (BAT). Intracerebroventricular (ICV) administration of insulin induced a similar pattern of tissue-specific FA partitioning. This effect of ICV insulin administration was not associated with activation of the insulin signaling pathway in adipose tissue. ICV administration of tolbutamide, a K(ATP) channel blocker, considerably reduced (during hyperinsulinemic-euglycemic clamp conditions) and even completely blocked (during ICV administration of insulin) WAT-specific retention of FA from plasma. This central effect of insulin was absent in CD36-deficient mice, indicating that CD36 is the predominant FA transporter in insulin-stimulated FA retention by WAT. In diet-induced insulin-resistant mice, these stimulating effects of insulin (circulating or ICV administered) on FA retention in WAT were lost. In conclusion, in insulin-sensitive mice, circulating insulin stimulates tissue-specific partitioning of plasma-derived FA in WAT in part through activation of K(ATP) channels in the CNS. Apparently, circulating insulin stimulates fatty acid uptake in WAT but not in BAT, directly and indirectly through the CNS.
authors.affiliation: Departments of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden, The Netherlands. C.P.Coomans@lumc.nl
authors.forename: Claudia P
authors.initials: CP
authors.lastname: Coomans
authors.forename: Janine J
authors.initials: JJ
authors.lastname: Geerling
authors.forename: Bruno
authors.initials: B
authors.lastname: Guigas
authors.forename: Anita M
authors.initials: AM
authors.lastname: van den Hoek
authors.forename: Edwin T
authors.initials: ET
authors.lastname: Parlevliet
authors.forename: D Margriet
authors.initials: DM
authors.lastname: Ouwens
authors.forename: Hanno
authors.initials: H
authors.lastname: Pijl
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Voshol
authors.forename: Patrick C N
authors.initials: PC
authors.lastname: Rensen
authors.forename: Louis M
authors.initials: LM
authors.lastname: Havekes
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Romijn
mesh_terms: D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000378:metabolism; D052436:Adipose Tissue, White / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D018955:CD36 Antigens / Q000235:genetics / Q000378:metabolism; D002490:Central Nervous System / Q000378:metabolism*; D004032:Diet; D005227:Fatty Acids / Q000378:metabolism*; D007328:Insulin / Q000097:blood* / Q000494:pharmacology; D054086:KATP Channels / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000503:physiopathology; D015398:Signal Transduction / Q000502:physiology
chemical_list: D018955:CD36 Antigens; D005227:Fatty Acids; D007328:Insulin; D054086:KATP Channels