Related Experiment Videos
Late effects of premature weaning to different diets in the rat
Insights
Early high-fat (HF) or high-carbohydrate (HG) diets in female rats influenced cholesterol metabolism and hormone levels, particularly after an atherogenic diet challenge. The high-fat diet group showed altered cholesterol clearance and a lower insulin/glucagon ratio.
Area of Science:
- Nutrition Science
- Metabolic Research
- Animal Models
Background:
- Dietary composition during early development can have long-lasting metabolic effects.
- Understanding the impact of early nutrition on adult lipid and glucose metabolism is crucial.
Purpose of the Study:
- To investigate the long-term effects of early high-fat (HF) versus high-carbohydrate (HG) diets on female rat metabolism.
- To assess the impact of these early diets on cholesterol homeostasis and hormonal profiles following an atherogenic challenge.
Main Methods:
- Female rats were weaned onto HF or HG diets, later switched to a stock diet, and then fed an atherogenic diet for two months.
- Measurements included blood cholesterol, 14C-cholesterol clearance, serum insulin and glucagon levels, and specific enzyme activities.
Main Results:
- Blood cholesterol levels varied between groups at different time points. 14C-cholesterol clearance differed between HF and HG groups after the atherogenic diet.
- Serum glucagon increased, and insulin decreased in the HF group, leading to a lower insulin/glucagon molar ratio compared to the HG group. Phosphoenolpyruvate carboxykinase activity was higher in the HG group.
Conclusions:
- Early diet composition significantly influences adult metabolic responses to dietary challenges, affecting cholesterol metabolism and the insulin-to-glucagon ratio.
- These findings highlight the critical role of early nutrition in programming long-term metabolic health and disease susceptibility.
Abstract:
Female rats were prematurely weaned on the 18th postnatal day to a high fat (HF) or high carbohydrate (HG) diet. Twelve days later they were all given free access to a cereal based stock diet. When aged 10 months, they were all fed an atherogenic diet for the next 2 months and were then killed. Blood cholesterol levels were higher in the HG group at 11 months but not 1 month later. After 2 months of feeding the atherogenic diet, injected 14C-cholesterol disappeared more slowly from the HF group during the first 24 hours after injection but more rapidly during the next 48 hours than the HG group. At that time, serum glucagon levels in the HF group had doubled but remained unchanged in the HG group. Serum insulin levels decreased significantly during that same period in the HF group but not the HG group. Consequently, the I/G molar ratio was lower in the HF than the HG group after 2 months of feeding the atherogenic diet. At 12 months, selected enzyme activities in white adipose tissue and liver did not differ between the two groups, except for phosphoenolpyruvate carboxykinase, the activity of which was higher in the HG