A Calcium-Deficient Diet in Rat Dams during Gestation and Nursing Affects Hepatic 11β-hydroxysteroid dehydrogenase-1 Expression in the Offspring

BACKGROUND Prenatal malnutrition can affect the phenotype of offspring by changing epigenetic regulation of specific genes. Several lines of evidence demonstrate that calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome. We hypothesized that pregnant female rats fed a Ca-deficient diet would have offspring with altered hepatic glucocorticoid-related gene expression and that lactation would modify these alterations. METHODOLOGY We determined the effects of Ca deficiency during pregnancy and/or lactation on hepatic 11β-hydroxysteroid dehydrogenase-1 (Hsd11b1) expression in offspring. Female Wistar rats consumed either a Ca-deficient (D: 0.008% Ca) or control (C: 0.90% Ca) diet ad libitum from 3 weeks preconception to 21 days postparturition. On postnatal day 1, pups were cross-fostered to the same or opposite dams and divided into the following four groups: CC, DD, CD, and DC (first letter: original mother's diet; second letter: nursing mother's diet). All offspring were fed a control diet beginning at weaning (day 21) and were killed on day 200 ± 7. Serum insulin and adipokines in offspring were measured using ELISA kits. PRINCIPAL FINDINGS In males, mean levels of insulin, glucose, and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) were higher in the DD and DC groups than in the CC group. We found no difference in HOMA-IR between the CC and CD groups in either males or females. Expression of Hsd11b1 was lower in male DD rats than in CC rats. Hsd11b1 expression in male offspring nursed by cross-fostered dams was higher than that in those nursed by dams fed the same diet; CC vs. CD and DD vs. DC. In females, Hsd11b1 expression in DC rats was higher than that in CC rats. CONCLUSIONS These findings indicated that maternal Ca restriction during pregnancy and/or lactation alters postnatal growth, Hsd11b1 expression, and insulin resistance in a sex-specific manner.