Pancreatic Ultrastructural Enhancement Due to Telmisartan Plus Sitagliptin Treatment in Diet-Induced Obese C57BL/6 Mice Vanessa Souza-Mello, RD, PhD, Bianca M. Grego ´rio, RD, PhD, Bernardo Relvas-Lucas, MD, Tatiane da Silva Faria, PhD, Marcia Barbosa Aguila, RD, PhD, and Carlos Alberto Mandarim-de-Lacerda, MD, PhD Objective: We sought to evaluate the effects of telmisartan, sitagliptin, or their combination on pancreatic ultrastructural alterations in high- fatYfed C57BL/6 mice. Methods: Three-month-old C57BL/6 mice were fed with standard chow (SC, 10% lipids) or high-fat diet (HF, 60% lipids) during 10 weeks to induce obesity and its comorbidities. After this period, treatment began (lasted 6 weeks), and the HF group was divided into 4 subgroups: un- treated HF, HF plus telmisartan (5 mg/kg per day), HF plus sitagliptin (1.1 g/kg per day), and HF plus telmisartan plus sitagliptin. Drugs were mixed with diet. Biochemical analyses, radioimmunoassay, immunoflu- orescence, stereology, and transmission electron microscopy were per- formed to assess pancreatic remodeling. Results: Overweight, hyperinsulinemia, hyperglycemia, and dyslipid- emia were found in the HF group, but these outcomes were controlled by the different treatments. Untreated HF animals also showed alterations concerning distribution of >/A cell followed by large and numerous lipid droplets within pancreas. Telmisartan and sitagliptin as monotherapy alleviated these findings, and a complete reversal of pancreatic steatosis was observed after treating with the combination of the 2 drugs. Conclusions: AT1 receptor blockade, partial peroxisome proliferator- activated receptor gamma activation, and extended incretin action emerge as feasible strategies to control pancreatic steatosis and avoid progres- sion of pancreatic diseases due to lipotoxicity. Key Words: NAFPD, pancreas ultrastructure, overweight, sitagliptin, telmisartan (Pancreas 2011;40: 715Y722) I nsulin resistance is closely related with long-term energy sur- plus. Initially, overnutrition triggers overweight and compen- satory hyperinsulinemia, which has been recently associated with ectopic lipid overload. 1 An abnormal amount of fatty acids within myocytes or hepatocytes disrupt insulin pathways, lead- ing to damage in the function and cytoarchitecture of these organs. 2,3 Excessive fatty acids may also target pancreas, where non- alcoholic fatty pancreatic disease (NAFPD) interferes with in- sulin secretion, leading to hypersecretion and islet hypertrophy, which in turn causes dysfunction and loss of A-cell through lipoapoptosis. 1,4 The persistence of this vicious cycle leads to pancreas exhaustion and overt type 2 diabetes mellitus (DM2). 5 Recent studies reveal that the progression of NAFPD to non- alcoholic steatopancreatitis is related to inflammatory state and enhanced oxidative stress. 6 To delay or to prevent this pro- gression, any kind of treatment that avoids lipid accumula- tion within the pancreatic tissue by promoting weight loss or increasing lipid oxidation seems to be useful once insulin resistance is the central factor of metabolic syndrome patho- physiology. 7 Metabolic syndrome, whose prevalence has been increasing worldwide, represents an enormous burden to central and developing countries nowadays, justifying the concern to find effective treatments. 8 Sitagliptin, alone or combined with other antidiabetic drugs, has been extensively used in clinical practice to control insulin resistance. 9,10 Sitagliptin exerts its effects based on ex- tended incretin action, leading to postprandial glycemic control, restoration of the normal synthesis, and release of insulin, all of which are crucial to increase pancreatic mass and avoid pan- creatic exhaustion in the long term. 11,12 On the other hand, tel- misartan, an antihypertensive drug, emerged as a promising strategy to restore insulin sensitivity. The combination of partial peroxisome proliferator-activated receptor gamma (PPARF) ac- tivation with angiotensin receptor blocker property leads to weight loss and suppression of inflammatory cytokines, which improve insulin sensitivity. Partial PPARF activation is impor- tant to avoid adverse effects from total activation such as fluid retention and adipogenesis. 13,14 Although telmisartan seems to exert beneficial effects on pancreatic structure, there is little in- formation about this. Our work aimed to evaluate the effects of telmisartan, as a monotherapy or combined with sitagliptin, on pancreatic remodeling. MATERIALS AND METHODS Animals and Diet All animal studies were performed according to the guide- lines of animal ethics committee of the State University of Rio de Janeiro, Rio de Janeiro, Brazil. All procedures were carried out in accordance with conventional guidelines for experimen- tation with animals (National Institutes of Health Publication No. 85-23, revised 1996), 15 and experimental protocols were approved by the local committee. Male C57BL/6 mice were maintained under controlled conditions (21 T 2-C, humidity 60% T 10%, 12:12-hour dark- light cycle) with free access to food and water until they were 3 months old. Then, they were randomly assigned to receive one of the following diets: a standard semipurified diet, a normoli- pidic diet (10 g of lipid/100-g diet), or a very high-fat semi- purified diet (60 g of lipid/100-g diet). The mineral and vitamin ORIGINAL ARTICLE Pancreas & Volume 40, Number 5, July 2011 www.pancreasjournal.com 715 From the Laboratory of Morphometry, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Rio de Janeiro, Brazil. Received for publication June 18, 2010; accepted January 27, 2011. Reprints: Carlos Alberto Mandarim-de-Lacerda, MD, PhD, Laborato ´rio de Morfometria e Morfologia Cardiovascular, Centro Biome ´dico, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Av 28 de Setembro 87 fds, 20551-030 Rio de Janeiro, RJ, Brazil (e-mail: mandarim@uerj.br; www.lmmc.uerj.br). This work was supported by the Brazilian agencies CNPQ (National Council of Science and Technology,http://www.cnpq.br) and Faperj (Rio de Janeiro Foundation for Research, http://www.faperj.br). Copyright * 2011 by Lippincott Williams & Wilkins Copyright © 2011 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.