Short-term exercise training early in life restores deficits in pancreatic β-cell mass associated with growth restriction in adult male rats

Laker RC, Gallo LA, Wlodek ME, Siebel AL, Wadley GD, McConell GK. Short-term exercise training early in life restores deficits in pancreatic beta-cell mass associated with growth restriction in adult male rats. Am J Physiol Endocrinol Metab 301: E931-E940, 2011. First published August 2, 2011; doi: 10.1152/ajpendo.00114.2011.-Fetal growth restriction is associated with reduced pancreatic beta-cell mass, contributing to impaired glucose tolerance and diabetes. Exercise training increases beta-cell mass in animals with diabetes and has long-lasting metabolic benefits in rodents and humans. We studied the effect of exercise training on islet and beta-cell morphology and plasma insulin and glucose, following an intraperitoneal glucose tolerance test ( IPGTT) in juvenile and adult male Wistar-Kyoto rats born small. Bilateral uterine vessel ligation performed on day 18 of pregnancy resulted in Restricted offspring born small compared with shamoperated Controls and also sham-operated Reduced litter offspring that had their litter size reduced to five pups at birth. Restricted, Control, and Reduced litter offspring remained sedentary or underwent treadmill running from 5 to 9 or 20 to 24 wk of age. Early life exercise increased relative islet surface area and beta-cell mass across all groups at 9 wk, partially restoring the 60-68% deficit ( P < 0.05) in Restricted offspring. Remarkably, despite no further exercise training after 9 wk, beta-cell mass was restored in Restricted at 24 wk, while sedentary littermates retained a 45% deficit ( P < 0.05) in relative beta-cell mass. Later exercise training also restored Restricted beta-cell mass to Control levels. In conclusion, early life exercise training in rats born small restored beta-cell mass in adulthood and may have beneficial consequences for later metabolic health and disease.