Research

Insulin sensitivity is normalized in the third generation (F3) offspring of developmentally programmed insulin resistant (F2) rats fed an energy-restricted diet

Daniel C Benyshek¹ , Carol S Johnston² , John F Martin³ and William D Ross⁴

¹Department of Anthropology, University of Nevada Las Vegas, 4505 Maryland, Parkway, Box 455003, Las Vegas, NV 89154-5003, USA

²Department of Nutrition, Arizona State University, Mesa, AZ, USA

³School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA

⁴College of Medicine, University of Arizona, Tucson, AZ, USA

author email corresponding author email

Nutrition & Metabolism 2008, 5:26doi:10.1186/1743-7075-5-26

Published:	17 October 2008

Abstract

Background/Aims

The offspring and grandoffspring of female rats fed low protein diets during pregnancy and lactation, but fed nutritionally adequate diets thereafter, have been shown to exhibit altered insulin sensitivity in adulthood. The current study investigates the insulin sensitivity of the offspring and grandoffspring of female rats fed low protein diets during pregnancy, and then maintained on energy-restricted diets post weaning over three generations.

Methods

Female Sprague Dawley rats (F0) were mated with control males and protein malnourished during pregnancy/lactation. F1 offspring were then weaned to adequate but energy-restricted diets into adulthood. F1 dams were fed energy-restricted diets throughout pregnancy/lactation. F2 offspring were also fed energy-restricted diets post weaning. F2 pregnant dams were maintained as described above. Their F3 offspring were split into two groups; one was maintained on the energy-restricted diet, the other was maintained on an adequate diet consumed ad libitum post weaning.

Results

F2 animals fed energy-restricted diets were insulin resistant (p < 0.05), while the insulin sensitivity of their F3 offspring equaled and surpassed that of controls on both the energy-restricted and adequate ad libitum postweaning diets (p < 0.05).

Conclusion

Maternal energy-restriction did not consistently program reduced insulin sensitivity in offspring over three consecutive generations. The reasons for this remain unclear. It is possible that the intergenerational transmission of developmentally programmed insulin resistance is determined in part by the relative insulin sensitivity of the mother during pregnancy/lactation.