Effects of maternal periconceptional undernutrition in sheep on offspring glucose–insulin axis function into adulthood

Abstract

AbstractMaternal periconceptional undernutrition (PCUN) affected fetal pancreatic maturation in late gestation lambs and impaired glucose tolerance in 10-month-old sheep. To examine the importance of the timing of maternal undernutrition around conception, a further cohort was born to PCUN ewes [undernourished for 61 d before conception (PreC), 30 d after conception (PostC), or 61 d before until 30 d after conception (PrePostC)], or normally fed ewes (Control) (n = 15–20/group). We compared glucose tolerance, insulin secretion, and sensitivity at 36 months of age. We also examined protein expression of insulin signalling proteins in muscle from these animals and in muscle from a fetal cohort (132 d of gestation; n = 7–10/group). Adult PostC and PrePostC sheep had higher glucose area under the curve than Controls (P = 0.07 and P = 0.02, respectively), whereas PreC sheep were similar to Controls (P = 0.97). PostC and PrePostC had reduced first-phase insulin secretion compared with Control (P = 0.03 and P = 0.02, respectively). PreC was similar to Control (P = 0.12). Skeletal muscle SLC2A4 protein expression in PostC and PrePostC was increased 19%–58% in fetuses (P = 0.004), but decreased 39%–43% in adult sheep (P = 0.003) compared with Controls. Consistent with this, protein kinase C zeta (PKCζ) protein expression tended to be increased in fetal (P = 0.09) and reduced in adult (P = 0.07) offspring of all PCUN ewes compared with Controls. Maternal PCUN alters several aspects of offspring glucose homeostasis into adulthood. These findings suggest that maternal periconceptional nutrition has a lasting impact on metabolic homeostasis of the offspring.