Underfeeding of rat mothers during the first two trimesters of gestation does not alter insulin action and insulin secretion in the progeny

Abstract

Portha B, Kergoat M, Blondel 0, Bailbe D. Underfeeding of rat mothers during the first two trimesters of gestation does not alter insulin action and insulin secretion in the progeny. Eur J Endocrinol 1995;133:475–82. ISSN 0804–4643 It has been suggested that impaired insulin action and/or insulin secretion in adult mammals could be a consequence of severe food restriction during fetal life. We have determined to what extent glucose homeostasis and insulin action are modified in male offspring of rats undernourished only during the first two trimesters of pregnancy. Pregnant females then were assigned to one of the following three experimental conditions. Rats in the first group had their food restricted to 50% of their pregnancy intake during the first 2 weeks of pregnancy, after which they were allowed to eat ad libitum. Rats in the second group were similarly restricted during the first 2 weeks, but beginning on day 14 of gestation were pair-fed to control rats until weaning on day 21 after birth. Such an experimental group was introduced because we observed that food-restricted mothers increased their food intake significantly above control levels in the last week of gestation and maintained this increase into the first postnatal week, when they were returned to ad libitum feeding on day 14 of gestation. Control rats (third group) were given access to food ad libitum throughout pregnancy and lactation. Offspring of mothers in the three groups are referred to as food-restricted/ad libitum refed (RA), food-restricted/ pair-refed (RP) and control (C) groups, respectively. From 6 weeks of age, RA males ate significantly more food and gained significantly more weight on a standard laboratory diet than control offspring. Maternal overeating after the restriction appears to be a necessary component in the aetiology of these effects because pair-refeeding mothers blocked the subsequent hyperphagia of male offspring fed the stock diet (RP group). In both the RA and RP groups, basal plasma glucose and insulin levels were not significantly different from those in control offspring and no alteration of the tolerance to intravenous glucose and the in vivo insulin secretory response to glucose was detected. Moreover, glucose utilization and endogenous glucose production were not impaired when measured either in the basal situation (postabsorptive state) or in hyperinsulinaemic conditions. Therefore, early food restriction of the mothers exerts no adverse effect upon insulin secretion and insulin action in the male offspring. B Portha, Lab. Physiopathology of Nutrition, CNRS URA 307, Université D. Diderot, Paris 7, 2 place Jussieu, Tour 33, 75251 Paris Cedex 05, France