ISSN:
1574-4647
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract In the present study we investigated the influence of long-term caloric restriction on blood glucose levels and the volume of the islets of Langerhans in the pancreases of mice. Thirty female F1 mice (SHN female × C3H male) were divided into two equal groups and raised for 11 months on either a slightly restricted “control” diet (95 Kcal per week) or a more severely restricted diet (50 Kcal per week), starting at time of weaning (4 weeks of age). These diets, designated as “isonutrient” (1), were designed so that both groups of animals received approximately equal amounts of minerals, proteins, fats and vitamins, but with carbohydrates adjusted to provide the desired calorie differences. Calorie-restricted animals (CR mice) were fed 3 days a week (Monday, Wednesday and Friday) with the restricted diet at 9:00 a.m., while control animals (C mice) were fed the control diets at 9:00 a.m. every day from Monday to Friday. On Sunday any leftover food was removed from the cages at 9:00 a.m. and both CR and C animals were allowed to fast. Fasting blood glucose levels were determined in the blood collected between 9:00 and 10:00 a.m. in 12-month-old mice from both groups on Saturday and on Monday 8 days later, at which time the mice were sacrificed for histological examination. The Saturday morning blood glucose levels (in mg/100 ml of blood) were lower in CR mice than in C mice (112±12 in CR mice and 145±16 in the C mice: p〈0.01). A similar trend was noted in the Monday morning samples: 80±19 in the CR and 108±28 in the C mice. In agreement with the blood glucose trends, histological examination of the pancreases demonstrated that the volume of the islets of Langerhans were significantly smaller in CR mice (Geometric mean 76646 μ3/islet, Geometric Standard deviation 2.10) than in C mice (Geometric mean 235578 μ m3/islet, Geometric Standard deviation 3.81)(p〈0.01). We conclude that caloric restriction decreases not only blood glucose levels, but reduces volumes of the islets of Langerhans.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02432371
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