Ileal transposition helps to regulate plasma hepatokine levels in obese Zucker (Crl:ZUC(ORL)-Leprfa) rats

We studied the long-term effect of ileal transposition (IT) metabolic surgery on the hepatokines: retinol-binding protein-4 (RBP4), α-2-HS-glycoprotein (aHSG/fetuin-A), and fibroblast growth factor 21 (FGF21), C-reactive protein (CRP) plasma levels, glucose metabolism, body weight, liver histology, as well as total lipids concentration in muscle, liver, and fat tissue of obese Zucker (Crl:ZUC(ORL)-Leprfa) rats. 14 adult males were randomly submitted either to IT or SHAM (control) surgery. Pre-operative hepatokines plasma levels were not significantly different in rats submitted to IT or SHAM protocol. Three months after the procedures the plasma levels of RBP4, aHSG, FGF21, and CRP were significantly lower in IT-operated animals when compared to SHAM-operated group. Three and 12 weeks after the IT and SHAM surgery, the AUCOGTT were significantly lower than AUCOGTT before the surgery. HOMA-IR was lower in rats after IT surgery in comparison to the SHAM-operated rats. Muscle and liver total lipids concentration was reduced after the IT procedure when compared to pre-IT conditions. IT had a significant reductive impact on the body weight in comparison to SHAM surgery in the 4th, 6th, 8th, and 10th week after the surgery. We conclude that IT reduces hepatokines’ plasma concentrations, muscle and liver total lipids concentration but not the inflammatory processes in the liver of Zucker (Crl:ZUC(ORL)-Leprfa) rats.

Ileal Transposition in Rats Reduces Energy Intake, Body Weight, and Body Fat Most Efficaciously When Ingesting a High-Protein Diet

Purpose Ileal transposition (IT) allows exploration of hindgut effects of bariatric procedures in inducing weight loss and reducing adiposity. Here we investigated the role of dietary macronutrient content on IT effects in rats. Methods Male Lewis rats consuming one of three isocaloric liquid diets enriched with fat (HF), carbohydrates (HC), or protein (HP) underwent IT or sham surgery. Body weight, energy intake, energy efficiency, body composition, and (meal-induced) changes in plasma GIP, GLP-1, PYY, neurotensin, and insulin levels were measured. Results Following IT, HC intake remained highest leading to smallest weight loss among dietary groups. IT in HF rats caused high initial weight loss and profound hypophagia, but the rats caught up later, and finally had the highest body fat content among IT rats. HP diet most efficaciously supported IT-induced reduction in body weight and adiposity, but (as opposed to other diet groups) lean mass was also reduced. Energy efficiency decreased immediately after IT irrespective of diet, but normalized later. Energy intake alone explained variation in post-operative weight change by 80%. GLP-1, neurotensin, and PYY were upregulated by IT, particularly during (0–60 min) and following 17-h post-ingestive intake, with marginal diet effects. Thirty-day post-operative cumulative energy intake was negatively correlated to 17-h post-ingestive PYY levels, explaining 47% of its variation. Conclusion Reduction in energy intake underlies IT-induced weight loss, with highest efficacy of the HP diet. PYY, GLP-1, and neurotensin levels are upregulated by IT, of which PYY may be most specifically related to reduced intake and weight loss after IT.

Impact of Ileal Transposition Surgical Intervention on Antioxidant Status Measured in Liver Tissue of Obese Zucker Rats (Crl:ZUC-Leprfa)

Background. The main factor characteristic for low-grade systemic inflammation typical for obesity is oxidative stress (OS). Reactive oxygen species (ROS) production is higher and more increased in time in the obese patients than in lean subjects. Aims. To assess the effect of ileal transposition (IT) and sham types of bariatric procedures on the antioxidative systems in the liver tissue of Zucker rats (Crl:ZUC Leprfa). Method. 21 animals were divided into the experimental groups: control group (n=7), sham group (n=7), and IT group (n=7). Sham and IT animals underwent selected surgery. The concentration of total antioxidant capacity (TAC), total antioxidant status (TOS), and activity of glutathione reductase (glutathione-disulfide reductase, GR, GSR), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and total superoxide dismutase activity (SOD) were assessed in liver tissue 3 months after surgery. Results. IT procedure significantly increased TAC when compared to sham and the control group. Animals after IT showed higher levels of TOS when compared to sham procedure. The total amount of TOS was similar in IT and control groups. GPx activity was increased in the groups submitted to the sham and IT surgery in relation to control. GR and CAT activities were significantly higher after IT in comparison to control and sham procedures. Total SOD and MnSOD were significantly higher in sham-operated animals in comparison to IT intervention and control groups. Conclusions. IT procedure had a positive impact on the diminishing of oxidative stress measured by TAC and TOS markers. The dynamic, adaptive, and protective mechanisms of enzymatic antioxidant systems were observed after the IT but not sham procedure. Nevertheless, 3 months after surgery, the midterm effect of bariatric surgery was observed, which might not fully balance the antioxidative response.