During the last decade, many epidemiological studies have shown that adult chronic metabolic (obesity, diabetes) and cardiovascular diseases may be determined, at least in part, during pregnancy through alterations of intrauterine environment. The “fetal programming” hypothesis implies that disturbances of the fetal development (intra uterine growth restriction – IUGR or macrosomia) increase the vulnerability to develop these pathologies in adulthood. To gain more insight into the mechanisms implicated in fetal programming, we used two experimental models of rodents (rat, mouse) and evaluated first the effect of an inhibition of the Rho-kinase pathway in utero on fetal growth and postnatal development in rats. In another study performed in mice, we aimed to assess the expression of apelin and its receptor APJ in obese and glucose intolerant mice fed with a high fat diet. Using data of this preliminary study, we speculated that this signaling system may be targeted during the pregnancy of obese mothers and could be implicated into the physiopathological consequences that may affect the fetoplacental unit. We demonstrated that pregnant rats treated by L-NAME, a NO synthase inhibitor (50 mg/day) were hypertensive and that their newborns presented a dramatic IUGR. Maternal treatment with the vasodilator Fasudil (10 mg/day) restored a normal maternal blood pressure and remarkably alleviated the fetal growth of L-NAME newborns. In adults, L-NAME male rats developed mild metabolic pathologies whereas rats exposed in utero to Fasudil presented an overweight, with hyperphagia and glucose intolerance. In obese and glucose intolerant mice fed with a high fat diet, we showed that apelin gene expression was altered in several organs (liver, kidney and adipose tissue) without any variation of apelin plasma concentration. Further studies are currently performed in our laboratory to unravel the expression of the apelin/APJ pathway in pregnant obese mice and their offsprings.
