Maternal zinc restriction affects postnatal growth and glucose homeostasis in rat offspring differently depending upon adequacy of their nutrient intake.

INTRODUCTION: We have previously investigated effects of moderate maternal zinc (Zn) restriction on growth and glucose homeostasis in offspring, but interaction between maternal Zn restriction and postnatal nutrition have not been studied.
RESULTS: Weight and serum Zn were lower in ZnD-IN than in ZnC-IN rats at wk 3, but ZnD-AN and ZnD-EN rats had greater weights than respective controls and higher insulin-like growth factor-1 (ZnD-AN) and leptin levels (ZnD-EN). Subsequently, both ZnD-AN and ZnD-EN pups were insulin resistant, and had evidence of elevated serum leptin and depressed insulin receptor phosphorylation with gender-specific differences up to 15 weeks. DISCUSSION: Maternal Zn restriction interacted with postnatal nutritional status, resulting in divergent effects on weight gain and insulin resistance. Interaction between potential effects of fetal Zn restriction and food availability postnatally may be one factor responsible for later metabolic derangements.
METHODS: Rats were fed Zn restricted (ZnD, 7 μg/g) or control (ZnC, 25 μg/g) diets ad libitum from 3 wk pre-conception to 3 wk post-parturition. Postnatally, litters were culled to 13 (IN, inadequate nutrition), 7 (AN, adequate nutrition), and 4 (EN, excess nutrition) pups/dam, respectively, and nursed by their original mothers. Postweaning, pups were fed rodent diet ad libitum. Tests to assess insulin resistance were performed subsequently.