Pancreatic and intestinal digestive enzymes in post-weanling rats with hypothalamic obesity

Male Sprague-Dawley rats received bilateral electrolytic lesions in the ventromedial hypothalamic nuclei (VMNL rats) at the age of 31 days; sham-lesioned rats served as controls. For 28 post-operative days all animals self-selected from three synthetic diets, each high in carbohydrate, fat and protein, respectively. Following this, half of the VMNL rats and half of the controls were switched to lab chow for 14 days. Body weights were comparable among the groups, but linear growth was greatly reduced and body fat (Lee Index) was elevated in VMNL rats, irrespective of diet. In the sham-lesioned controls, the synthetic diets reduced most parameters of exocrine pancreatic activity. In VMNL rats, in contrast, pancreatic parameters were unaffected by the synthetic diet. The data suggest that VMN lesions disinhibit the exocrine pancreas. In contrast, most parameters of intestinal activity were not influenced by VMN lesions.