title: Quantification of total and visceral adipose tissue in fructose-fed rats using water-fat separated single echo MRI.
abstract: OBJECTIVE
  The aim of this study was to setup a rodent model for modest weight gain and an MRI-based quantification of body composition on a clinical 1.5 T MRI system for studies of obesity and environmental factors and their possible association.
  
  
  METHODS
  Twenty-four 4-week-old female Fischer rats were divided into two groups: one exposed group (n = 12) and one control group (n = 12). The exposed group was given drinking water containing fructose (5% for 7 weeks, then 20% for 3 weeks). The control group was given tap water. Before sacrifice, whole body MRI was performed to determine volumes of total and visceral adipose tissue and lean tissue. MRI was performed using a clinical 1.5 T system and a chemical shift based technique for separation of water and fat signal from a rapid single echo acquisition. Fat signal fraction was used to separate adipose and lean tissue. Visceral adipose tissue volume was quantified using semiautomated segmentation. After sacrifice, a perirenal fat pad and the liver were dissected and weighed. Plasma proteins were analyzed by Western blot.
  
  
  RESULTS
  The weight gain was 5.2% greater in rats exposed to fructose than in controls (P = 0.042). Total and visceral adipose tissue volumes were 5.2 cm3 (P = 0.017) and 3.1 cm3 (P = 0.019) greater, respectively, while lean tissue volumes did not differ. The level of triglycerides and apolipoprotein A-I was higher (P = 0.034, P = 0.005, respectively) in fructose-exposed rats.
  
  
  CONCLUSIONS
  The setup induced and assessed a modest visceral obesity and hypertriglyceridemia, making it suitable for further studies of a possible association between environmental factors and obesity.
authors.affiliation: Occupational and Environmental Medicine, Uppsala University, Uppsala, Sweden.
authors.forename: Monika
authors.initials: M
authors.lastname: Rönn
authors.forename: P Monica
authors.initials: PM
authors.lastname: Lind
authors.forename: Helen
authors.initials: H
authors.lastname: Karlsson
authors.forename: Katarina
authors.initials: K
authors.lastname: Cvek
authors.forename: Johan
authors.initials: J
authors.lastname: Berglund
authors.forename: Filip
authors.initials: F
authors.lastname: Malmberg
authors.forename: Jan
authors.initials: J
authors.lastname: Orberg
authors.forename: Lars
authors.initials: L
authors.lastname: Lind
authors.forename: Francisco
authors.initials: F
authors.lastname: Ortiz-Nieto
authors.forename: Joel
authors.initials: J
authors.lastname: Kullberg
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D016632:Apolipoprotein A-I / Q000097:blood; D001823:Body Composition / Q000187:drug effects; D001825:Body Fluid Compartments / Q000378:metabolism; D004195:Disease Models, Animal; D002149:Energy Intake; D005260:Female; D005632:Fructose / Q000009:adverse effects*; D015228:Hypertriglyceridemia / Q000097:blood / Q000139:chemically induced / Q000378:metabolism; D050152:Intra-Abdominal Fat / Q000187:drug effects / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods; D056128:Obesity, Abdominal / Q000097:blood / Q000139:chemically induced / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D014280:Triglycerides / Q000097:blood; D015430:Weight Gain / Q000187:drug effects
chemical_list: D016632:Apolipoprotein A-I; D014280:Triglycerides; D005632:Fructose