Growth and protein metabolism in exercised, estrogen-fed and developing female Zucker rats

Abstract

Statement of Rationale Experiment 1: Effects of exercise on growth and 3-methyIhistidine excretion of female Zucker rats Experiment 2: Effects of ethynyl estradiol on body composition growth and muscle protein catabolism of female Zucker rats Experiment 3: Development and protein metabolism of female Zucker rats 4 REVIEW OF LITERATURE The Zucker Rat as a Model of Obesity Relationship of hyperphagia and body protein content to the obesity of the Zucker rat 7 Evidence for Subnormal Estrogen Status of Female Zucker Rats ... 10 Protein Turnover in Rats 12 Protein synthesis 13 Regulation of protein synthesis 13 Measurement of protein synthesis 14 Protein degradation and 3-methylhistidine excretion 15 Urinary 3-MH as an indicator of skeletal muscle catabolism. . 16 Protein Metabolism in the Zucker Rat 17 Exercise Studies in Rats 19 Food intake and body composition of treadmill exercised rats 20 Effects of exercise on protein turnover in rats 21 Effects of exercise on food intake and body composition of Zucker rats 23 Interrelationship of Protein Metabolism, Corticosterone and Obesity in the Zucker Rat 25 Effects of corticosterone in normal rats 25 Relationships of corticosterone to the obesity of the Zucker rat 27 Effect of adrenalectomy on the obese Zucker rat 28 EXPERIMENT 1: EFFECTS OF EXERCISE ON GROWTH AND 3-METHYLHISTIDINE EXCRETION OF FEMALE ZUCKER RATS Introduction iii Methods Results Weight gain and food intake Body composition and organ weights Urinary 3-methylhistidine Discussion Weight gain and food intake Body composition and organ weights Urinary 3-methylhistidine EXPERIMENT 2: EFFECTS OF ETHYNYL ESTRADIOL ON BODY COMPOSITION, GROWTH AND 3-METHYLHISTIDINE EXCRETION OF FEMALE ZUCKER RATS .... Introduction 49 Methods 50 Results 52 Body weight and weight gain 52 Body composition and organ weights 52 Urinary 3-methylhistidine excretion 54 Discussion 54 Body weight and weight gain 54 Body composition and organ weights 58 Urinary 3-methylhistidine 69 EXPERIMENT 3: DEVELOPMENT AND PROTEIN METABOLISM OF FEMALE ZUCKER RATS 71 Discussion 76 Body composition 76 Incorporation of ^H-phenylalanine 84 Urinary 3-methylhistidine excretion 86 GENERAL DISCUSSION 89