Fostering in mice induces cardiovascular and metabolic dysfunction in adulthood

Non-technical summary Cross-fostering of newborn pups to different dams is a method widely used in rodent studies of developmental ‘programming’ to determine whether pregnancy or the suckling period is more important in determining adult characteristics following changes to the maternal environment. We have investigated whether the process of fostering per se influences cardiovascular and metabolic development in mice. Compared with mice reared by their biological mother, fostered mice showed increased appetite, body weight, abdominal fatness and altered blood sugar metabolism. A marked increase in blood pressure was also apparent. This study demonstrates that the process of fostering can lead to profound effects in cardiovascular and metabolic function in otherwise normal mice. The findings have implications both for the interpretation of previous cross-fostering studies in mice and for studies investigating the hypothesis of developmental programming, in which early postnatal manipulation of litters is common practice.