In the rat, dexamethasone treatment during late pregnancy leads to intrauterine growth retardation and is used as a model of early programming of adult onset disease. The present study investigated whether pre-natal dexamethasone treatment modifies cardiac glucose transporter (GLUT) protein expression in adulthood and identified signalling pathways involved in the response. Dexamethasone (100 µg/kg body wt per day) administered via an osmotic pump to pregnant rats (day 15 to day 21; term=22 to 23 days) reduced fetal weight at day 21 and caused hypertension, hyperinsulinaemia and elevated corticosterone levels in the adult (24-week-old) male offspring. Cardiac GLUT1 protein expression was selectively up-regulated (2·5-fold; P<0·001), in the absence of altered cardiac GLUT4 protein expression, in adult male offspring of dexamethasone-treated dams. Maternal dexamethasone treatment did not influence cardiac GLUT1 protein expression during fetal or early post-natal life. We examined potential regulatory signalling proteins that might mediate up-regulation of cardiac GLUT1 protein expression in adulthood. We observed marked (2·2-fold; P<0·01) activation of Akt/protein kinase B (PKB), together with modest activation of the anti-apoptotic protein kinase C (PKC) isoforms PKC (88%, P<0·05) and PKC ε (56%, P<0·05) in hearts of the early-growth-retarded male offspring. These effects were, however, observed in conjunction with up-regulation of cardiac protein expression of PKC 1 (191%, P<0·01), PKC 2 (49%, P<0·05) and PKC (35%; P<0·01), effects that may have adverse consequences. Maternal dexamethasone treatment was without effect on cardiac extracellular signal-related kinase (ERK) 1 or ERK2 activity in adulthood. In conclusion, our data demonstrate an effect of maternal dexamethasone treatment to up-regulate cardiac GLUT1 protein expression in early-growth-retarded, hypertensive, hyperinsulinaemic adult male offspring, an effect observed in conjunction with activation of Akt/PKB.