Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2014 The effects of heat stress on energetic metabolism and insulin homeostasis María Victoria Sanz Fernández Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Agriculture Commons, Animal Sciences Commons, Endocrinology Commons, Endocrinology, Diabetes, and Metabolism Commons, and the Environmental Sciences Commons Recommended Citation Sanz Fernández, María Victoria, "The effects of heat stress on energetic metabolism and insulin homeostasis" (2014). Graduate Theses and Dissertations. 14292. https://lib.dr.iastate.edu/etd/14292 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. The effects of heat stress on energetic metabolism and insulin homeostasis by María Victoria Sanz Fernández A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Nutritional Sciences Program of Study Committee: Lance H. Baumgard, Major Professor Nicholas K. Gabler Aileen F. Keating Michael E. Spurlock Christopher K. Tuggle Iowa State University Ames, Iowa 2014 Copyright © María Victoria Sanz Fernández, 2014. All rights reserved. ii DEDICATION A mi familia. En especial a mis padres, porque sin ellos no sería. Por compartir mis alegrías y apoyarme en cada fracaso, especialmente durante los últimos cuatro años en los que habéis hecho que la distancia no existiera. Os quiero mucho. Toyita iii TABLE OF CONTENTS Page LIST OF FIGURES............................................................................................................. vi LIST OF TABLES.............................................................................................................. viii NOMENCLATURE............................................................................................................ x ACKNOWLEDGEMENTS................................................................................................ xii ABSTRACT........................................................................................................................ xiv CHAPTER 1: LITERATURE REVIEW............................................................................ 1 Impact of Heat Stress.................................................................................................... 1 Animal agriculture...................................................................................................... 1 Human impact............................................................................................................ 2 Insulin Metabolism........................................................................................................ 3 Insulin synthesis......................................................................................................... 4 Insulin secretion......................................................................................................... 4 Insulin secretagogues................................................................................................. 5 Insulin signaling......................................................................................................... 7 Integrative Metabolism.................................................................................................. 9 Effects of Heat Stress on Metabolism........................................................................... 11 Protein metabolism..................................................................................................... 12 Lipid metabolism........................................................................................................ 12 Carbohydrate metabolism........................................................................................... 13 Insulin homeostasis.................................................................................................... 16 Heat Stress and Intestinal Barrier Function................................................................... 20 Similarities between heat stress and endotoxemia..................................................... 21 Summary....................................................................................................................... 22 . CHAPTER 2: EFFECTS OF HEAT STRESS ON BASAL AND STIMULATED METABOLISM........................................................................................ 24 Abstract......................................................................................................................... 25 Introduction................................................................................................................... 26 Materials and Methods.................................................................................................. 27 Animals and experimental design.............................................................................. 27 Blood sampling and metabolic challenges................................................................. 28 Blood parameters analyses......................................................................................... 29 Hepatic 5’-deiodinase type I activity.......................................................................... 30 Pancreatic insulin content........................................................................................... 31 iv Pancreatic immunohistochemistry............................................................................. 31 RNA isolation and quantitative PCR.......................................................................... 32 Calculations and statistical analysis........................................................................... 32 Results........................................................................................................................... 33 Discussion..................................................................................................................... 36 CHAPTER 3: EFFECTS OF HEAT STRESS ON INSULIN SENSITIVITY................... 54 Abstract......................................................................................................................... 54 Introduction................................................................................................................... 55 Materials and Methods.................................................................................................. 57 Animals and experimental design.............................................................................. 57 Daily blood sampling................................................................................................. 58 Hyperinsulinemic euglycemic clamp......................................................................... 58 Insulin tolerance test................................................................................................... 59 Blood parameters analyses......................................................................................... 59 Western blotting......................................................................................................... 60 Calculations and statistical analysis........................................................................... 60 Results........................................................................................................................... 61 Discussion..................................................................................................................... 63 CHAPTER 4: EFFECTS OF SUPPLEMENTAL ZINC AMINO ACID COMPLEX ON GUT INTEGRITY IN HEAT-STRESSED GROWING PIGS................ 76 Abstract......................................................................................................................... 76 Implications................................................................................................................... 77 Introduction................................................................................................................... 78 Materials and Methods.................................................................................................. 79 Animals and experimental design.............................................................................. 79 Ussing chambers......................................................................................................... 82 Histology.................................................................................................................... 82 Blood parameters analyses......................................................................................... 83 Statistical analysis...................................................................................................... 83 Results........................................................................................................................... 83 Discussion..................................................................................................................... 85 CHAPTER 5: EFFECTS OF DAIRY PRODUCTS ON INTESTINAL INTEGRITY IN HEAT-STRESSED PIGS.......................................................................