Related Experiment Videos
Growth and metabolic parameters in pups of undernourished lactating rats
J Boxwell1, P Ayson, M Ramenofsky
1Department of Zoology, University of Washington, Seattle 98195, USA.
Insights
Reduced nutrition in early life impairs growth and alters key hormones. Nutritional deprivation affects corticosterone-binding globulin, reducing corticosterone
Area of Science:
- Endocrinology
- Developmental Biology
- Nutritional Science
Background:
- Postnatal development is critical for long-term health.
- Early-life nutrition significantly impacts physiological programming.
- Hormonal regulation is sensitive to nutritional status during development.
Purpose of the Study:
- To investigate the effects of nutritional restriction during lactation on preweanling rat pups.
- To assess the impact on body weight, metabolic parameters, and the corticosterone-binding globulin (CBP) system.
- To understand how nutritional deprivation affects the regulation of corticosterone.
Main Methods:
- Long Evans rat pups were divided into control and nutritionally restricted litters.
- Dams in restricted litters received 1/3 of the chow given to controls.
- Measurements included body weight, plasma corticosterone, CBP binding capacity and affinity (Kd), plasma glucose, and body composition.
Main Results:
- Restricted pups showed lower body weight, percent body lipid, plasma corticosterone, and glucose by 11 days.
- CBP binding capacity was reduced in restricted pups, with an increased binding affinity (Kd).
- Nutritional deprivation impaired CBP production, reducing corticosterone's biological activity.
Conclusions:
- Nutritional deprivation during lactation negatively impacts postnatal growth and metabolic parameters in rat pups.
- Reduced nutrition alters the corticosterone-binding globulin system, affecting corticosterone bioavailability.
- Early-life nutritional stress compromises the pups' ability to manage energy metabolism during a critical growth period.
Abstract:
Effects of reduced nutrition during postnatal development were studied by measuring body weight, plasma corticosterone, corticosterone-binding globulin (CBP), and metabolic parameters (plasma glucose and body composition) in preweanling Long Evans rat pups. Control litters consisted of dams that were fed chow ad lib while restricted dams were provided 1/3 the amount of chow given controls (25-30 g/day). At 11 days, body weight of the restricted pups dropped below that of controls. Percent body lipid, plasma corticosterone and glucose of restricted pups were lower than controls. Binding capacity of CBP in controls increased without a change in binding affinity (Kd). By contrast, binding capacity of CBP of restricted pups never matched that of controls but the Kd increased. Nutritional deprivation during lactation affected production of CBP that effectively reduced the biological activity of corticosterone in circulation. Deprived of an effective cellular response to an impoverished supply of food, pups were left with little capacity to manage endogenous fuels during the growth spurt that normally occurs during the suckling period.