TY  - JOUR
A1  - Hankir, Mohammed K.
A1  - Patt, Marianne
A1  - Patt, Jörg T. W.
A1  - Becker, Georg A.
A1  - Rullmann, Michael
A1  - Kranz, Mathias
A1  - Deuther-Conrad, Winnie
A1  - Schischke, Kristin
A1  - Seyfried, Florian
A1  - Brust, Peter
A1  - Hesse, Swen
A1  - Sabri, Osama
A1  - Krügel, Ute
A1  - Fenske, Wiebke
T1  - Suppressed fat appetite after Roux-en-Y gastric bypass surgery associates with reduced brain mu-opioid receptor availability in diet-induced obese male rats
JF  - Frontiers in Neuroscience
N2  - Brain μ-opioid receptors (MORs) stimulate high-fat (HF) feeding and have been implicated in the distinct long term outcomes on body weight of bariatric surgery and dieting. Whether alterations in fat appetite specifically following these disparate weight loss interventions relate to changes in brain MOR signaling is unknown. To address this issue, diet-induced obese male rats underwent either Roux-en-Y gastric bypass (RYGB) or sham surgeries. Postoperatively, animals were placed on a two-choice diet consisting of low-fat (LF) and HF food and sham-operated rats were further split into ad libitum fed (Sham-LF/HF) and body weight-matched (Sham-BWM) to RYGB groups. An additional set of sham-operated rats always only on a LF diet (Sham-LF) served as lean controls, making four experimental groups in total. Corresponding to a stage of weight loss maintenance for RYGB rats, two-bottle fat preference tests in conjunction with small-animal positron emission tomography (PET) imaging studies with the selective MOR radioligand [\(^{11}\)C]carfentanil were performed. Brains were subsequently collected and MOR protein levels in the hypothalamus, striatum, prefrontal cortex and orbitofrontal cortex were analyzed by Western Blot. We found that only the RYGB group presented with intervention-specific changes: having markedly suppressed intake and preference for high concentration fat emulsions, a widespread reduction in [\(^{11}\)C]carfentanil binding potential (reflecting MOR availability) in various brain regions, and a downregulation of striatal and prefrontal MOR protein levels compared to the remaining groups. These findings suggest that the suppressed fat appetite caused by RYGB surgery is due to reduced brain MOR signaling, which may contribute to sustained weight loss unlike the case for dieting.
KW  - bariatric surgery
KW  - caloric-restriction
KW  - fat appetite
KW  - Brain μ-opioid receptors
KW  - positron emission tomography imaging
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-181130
VL  - 10
ER  -