Chronic inflammation in childhood is associated with impaired growth. In the current study, a lipopolysaccharide (LPS) model of inflammation in young rats was used to study the efficacy of whey-based as compared to soy-based diets to ameliorate growth attenuation. Young rats were injected with LPS and fed normal chow or diets containing whey or soy as the sole protein source during treatment, or during the recovery period in a separate set of experiments. The body and spleen weight, food consumption, humerus length, and EGP height and structure were evaluated. Inflammatory markers in the spleen and markers of differentiation in the EGP were assessed using qPCR. The LPS led to a significant increase in the spleen weight and a decrease in the EGP height. Whey, but not soy, protected the animals from both effects. In the recovery model, whey led to increased EGP height at both 3 and 16 d post treatment. The most affected region in the EGP was the hypertrophic zone (HZ), which was significantly shortened by the LPS treatment but enlarged by whey. In conclusion, LPS affected the spleen weight and EGP height and had a specific effect on the HZ. Nutrition with whey protein appeared to protect the rats from the LPS-induced growth attenuation.
Keywords: LPS; growth plate; hypertrophic zone; inflammation; soy; whey.