title: Increase in visceral fat per se does not induce insulin resistance in the canine model.
abstract: OBJECTIVE
  To determine whether a selective increase of visceral adipose tissue content will result in insulin resistance.
  
  
  METHODS
  Sympathetic denervation of the omental fat was performed under general inhalant anesthesia by injecting 6-hydroxydopamine in the omental fat of lean mongrel dogs (n = 11). In the conscious animal, whole-body insulin sensitivity was assessed by the minimal model (SI ) and the euglycemic hyperinsulinemic clamp (SICLAMP ). Changes in abdominal fat were monitored by magnetic resonance. All assessments were determined before (Wk0) and 2 weeks (Wk2) after denervation. Data are medians (upper and lower interquartile).
  
  
  RESULTS
  Denervation of omental fat resulted in increased percentage (and content) of visceral fat [Wk0: 10.2% (8.5-11.4); Wk2: 12.4% (10.4-13.6); P < 0.01]. Abdominal subcutaneous fat remained unchanged. However, no changes were found in SI [Wk0: 4.7 (mU/l)(-1) min(-1) (3.1-8.8); Wk2: 5.3 (mU/l)(-1) min(-1) (4.5-7.2); P = 0.59] or SICLAMP [Wk0: 42.0 × 10(-4) dl kg(-1) min(-1) (mU/l)(-1) (41.0-51.0); Wk2: 40.0 × 10(-4) dl kg(-1) min(-1) (mU/l) (-1) (34.0-52.0); P = 0.67].
  
  
  CONCLUSIONS
  Despite a selective increase in visceral adiposity in dogs, insulin sensitivity in vivo did not change, which argues against the concept that accumulation of visceral adipose tissue contributes to insulin resistance.
authors.affiliation: Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Ana V B
authors.initials: AV
authors.lastname: Castro
authors.forename: Orison O
authors.initials: OO
authors.lastname: Woolcott
authors.forename: Malini S
authors.initials: MS
authors.lastname: Iyer
authors.forename: Morvarid
authors.initials: M
authors.lastname: Kabir
authors.forename: Viorica
authors.initials: V
authors.lastname: Ionut
authors.forename: Darko
authors.initials: D
authors.lastname: Stefanovski
authors.forename: Cathryn M
authors.initials: CM
authors.lastname: Kolka
authors.forename: Lidia S
authors.initials: LS
authors.lastname: Szczepaniak
authors.forename: Edward W
authors.initials: EW
authors.lastname: Szczepaniak
authors.forename: Isaac
authors.initials: I
authors.lastname: Asare-Bediako
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Paszkiewicz
authors.forename: Josiane L
authors.initials: JL
authors.lastname: Broussard
authors.forename: Stella P
authors.initials: SP
authors.lastname: Kim
authors.forename: Erlinda L
authors.initials: EL
authors.lastname: Kirkman
authors.forename: Hernan C
authors.initials: HC
authors.lastname: Rios
authors.forename: Hasmik
authors.initials: H
authors.lastname: Mkrtchyan
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wu
authors.forename: Marilyn
authors.initials: M
authors.lastname: Ader
authors.forename: Richard N
authors.initials: RN
authors.lastname: Bergman
mesh_terms: D000818:Animals; D001823:Body Composition; D001835:Body Weight; D004285:Dogs; D015309:Glucose Clamp Technique; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000033:anatomy & histology* / Q000294:innervation / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D023421:Models, Animal; D009852:Omentum / Q000294:innervation; D009929:Organ Size; D050507:Subcutaneous Fat, Abdominal / Q000033:anatomy & histology / Q000294:innervation / Q000378:metabolism; D013563:Sympathectomy, Chemical / Q000662:veterinary