title: High fat/carbohydrate ratio but not total energy intake induces lower striatal dopamine D2/3 receptor availability in diet-induced obesity.
abstract: High-energy diets that induce obesity decrease striatal dopamine D2/3 receptor (DRD2/3) availability. It is however poorly understood which components of these diets are underlying this decrease. This study assessed the role of saturated fat intake on striatal DRD2/3 availability. Forty rats were randomized to a free-choice high-fat high-sugar diet (HFHS) or a standard chow diet for 28 days. Striatal DRD2/3 availability was measured using (123)I-IBZM storage phosphor imaging at day 29. The HFHS group was split in a HFHS-high-fat (HFHS-hf) and HFHS-low-fat (HFHS-lf) group based on the percentage energy intake from fat. Rats of both HFHS subgroups had increased energy intake, abdominal fat stores and plasma leptin levels compared with controls. DRD2/3 availability in the nucleus accumbens (NAcc) was significantly lower in HFHS-hf than in HFHS-lf rats, whereas it was similar for HFHS-lf and control rats. Furthermore, DRD2/3 availability in the NAcc was positively correlated with the percentage energy intake from sugar. Total energy intake was lower for HFHS-hf than for HFHS-lf rats. Together these results suggest that a diet with a high fat/carbohydrate ratio, but not total energy intake or the level of adiposity, is the best explanation for the decrease in striatal DRD2/3 availability observed in diet-induced obesity.
authors.affiliation: Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. elsmariekevandegiessen@gmail.com
authors.forename: E
authors.initials: E
authors.lastname: van de Giessen
authors.forename: S E
authors.initials: SE
authors.lastname: la Fleur
authors.forename: L
authors.initials: L
authors.lastname: Eggels
authors.forename: K
authors.initials: K
authors.lastname: de Bruin
authors.forename: W
authors.initials: W
authors.lastname: van den Brink
authors.forename: J
authors.initials: J
authors.lastname: Booij
mesh_terms: D000818:Animals; D001549:Benzamides; D001682:Biological Availability; D003287:Contrast Media; D003342:Corpus Striatum / Q000378:metabolism*; D004032:Diet; D059305:Diet, High-Fat; D004040:Dietary Carbohydrates / Q000378:metabolism; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism*; D019422:Dietary Sucrose / Q000008:administration & dosage / Q000378:metabolism*; D018492:Dopamine Antagonists; D002149:Energy Intake; D005247:Feeding Behavior; D008297:Male; D009765:Obesity / Q000209:etiology / Q000378:metabolism*; D011759:Pyrrolidines; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3 / Q000378:metabolism*
chemical_list: D001549:Benzamides; D003287:Contrast Media; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D019422:Dietary Sucrose; D018492:Dopamine Antagonists; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide