Maternal nutrient restriction in guinea pigs as an animal model for studying growth-restricted offspring with postnatal catch-up growth

Catherine L. Nevin, Evan Formosa, Yohei Maki, Brad Matushewski, Timothy R. H. Regnault, Bryan S. Richardson
2018 American Journal of Physiology. Regulatory Integrative and Comparative Physiology  
Nevin CL, Formosa E, Maki Y, Matushewski B, Regnault TR, Richardson BS. Maternal nutrient restriction in guinea pigs as an animal model for studying growth-restricted offspring with postnatal catch-up growth. We determined the impact of moderate maternal nutrient restriction (MNR) in guinea pigs with fetal growth restriction (FGR) on offspring body and organ weights, hypothesizing that FGR-MNR animals will show catch-up growth but with organspecific differences. Guinea pig sows were fed ad
more » ... ws were fed ad libitum (Control) or 70% of the control diet from 4 weeks preconception, switching to 90% at midpregnancy (MNR). Control newborns Ͼ95 g [appropriate for gestational age (AGA); n ϭ 37] and MNR newborns Ͻ85 g (FGR; n ϭ 37) were monitored until neonatal (~25 days) or adult (~110 days) necropsy. Birth weights and body/organ weights at necropsy were used to calculate absolute and fractional growth rates (FRs). FGR-MNR birth weights were decreased~32% compared with the AGA-Controls. FGR-MNR neonatal whole body FRs were increased~36% compared with Controls indicating catch-up growth, with values negatively correlated to birth weights indicating the degree of FGR leads to greater catch-up growth. However, the increase in organ FRs in the FGR-MNR neonates compared with Controls was variable, being similar for the brain and kidneys indicating comparable catch-up growth to that of the whole body and twofold increased for the liver but negligible for the heart indicating markedly increased and absent catch-up growth, respectively. While FGR-MNR body and organ weights were unchanged from the AGA-Controls by adulthood, whole body growth rates were increased. These findings confirm early catch-up growth in FGR-MNR guinea pigs but with organ-specific differences and enhanced growth rates by adulthood, which are likely to have implications for structural alterations and disease risk in later life. fetal growth restriction; maternal undernourishment; postnatal catch-up growth
doi:10.1152/ajpregu.00317.2017 pmid:29351419 fatcat:invrei6afnabdldyqxi7wqxnlq