Investigations on obesity and experimental hyperlipaemia.

The results of experiments in an animal model for obesity, namely obese hyperglycaemic mice (ob/ob) are described and their relevance to the study of obesity and endogenous hyperlipaemia in man is discussed. Alternating periods of fasting and refeeding reduced the body weight, blood glucose, and plasma insulin levels of obese hyperglycaemic (ob/ob) mice, which also showed an increase in physical activity. A return to normal feeding habit reversed these changes. ob/ob mice showed no weight loss when treated with various doses of triiodothyronine (T[3]), 'slim' ob/ob mice did not breed, and an unexpected number of lipomas at the tail of the pancreas was discovered in these animals. A study of changes in the distribution and numbers of gut hormone-producing cells in these mice was commenced and the possibility that these 'insulin-releasing' gastrointestinal hormones may be involved in the development of obesity is discussed