The effect of obesity and non-insulin dependent diabetes mellitus on insulin, IGF-I, and IGF-II stimulated glucose transport in human muscle / by Charles W. Elton.
| Author/creator | Elton, Charles W. author. |
| Other author | Dohm, G. Lynis, degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 1990. |
| Description | iv, 55 pages, 30 unnumbered leaves : illustrations ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | The purpose of this study is to investigate the effects of obesity on glucose transport in human muscle. Insulin resistance in peripheral tissues has been observed in obesity with and without insulin dependent diabetes melletus (NIDDM). The cellular mechanism responsible for this decrease has been partially characterized in rat adipose and muscle, and human adipose. However, due to the difficulty in obtaining human muscle samples, and a suitable in vitro incubation method, little research has been done to characterize glucose transport in human muscle, the major tissue of glucose disposal in humans. In collaboration with the surgery department at Pitt County Memorial Hospital, the laboratory of G. Lynis Dohm, Ph.D. at East Carolina University School of Medicine has access to samples of human muscle tissue appropriate for in vitro incubation. Control muscle was obtained from nondiabetic, lean patients entering the hospital for total abdominal hysterectomies. Muscle from morbidly obese-nondiabetic and morbidly obese-diabetic subjects was obtained from patients entering the hospital for gastric bypass surgery for weight reduction. The first hypothesis of this research was that obesity and obesity accompanied by diabetes is associated with impaired glucose transport in in vitro incubated human muscle. To test this hypothesis muscle fibers from the three groups of patients were incubated in vitro with insulin, IGF-I or IGF-II hormones which stimulate glucose transport. The maximum rate of hormone stimulated transport in each group was significantly decreased in obese-nondiabetic and obese-diabetic subjects compared to controls. The second hypothesis of this research was that the decrease in transport seen in obese subjects, with or without NIDDM, was due to decreased numbers of glucose transporter proteins in skeletal muscle. Western blots were done on muscle samples from the three patient groups to measure relative amounts of muscle glucose transporter (GLUT4). Experiments demonstrated that glucose transporters are decreased in skeletal muscle from obese-nondiabetic and obese-diabetic individuals. The third hypothesis of this research was that an obesity threshold exists above which glucose transport precipitously decreases. Analysis of hormone stimulated rates of glucose transport in lean patients and those with moderate obesity indicated that no threshold exists. Glucose transport decreased in a linear manner in subjects with body mass ranging from lean to moderately obese. |
| General note | Submitted to the faculty of the Department of Biology. |
| General note | Advisor: G. Lynis Dohm |
| Dissertation note | M.S. East Carolina University 1990 |
| Bibliography note | Includes bibliographical references (leaves 51-55). |
| Genre/form | dissertations. |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |