Do alterations in placental @entity11331 dehydrogenase (11betaHSD) activities explain differences in fetal @entity2339 following periconceptional undernutrition or twinning in XXXX ?

@entity821 @entity742 @entity73087 @entity600 @entity2339 @entity701 @entity11331
Periconceptional undernutrition (UN) in @entity742 accelerates fetal @entity2339 activation, resulting in @entity600 . In contrast, twin conception suppresses fetal HPA function and delays prepartum HPA activation. We hypothesized that these dissimilar effects on fetal HPA activity result from different influences of maternal glucocorticoid (GC) on maturation of the fetal @entity2339 , mediated via different activities of placental @entity11331 dehydrogenase (11betaHSD) isozymes. We examined the effects of twinning and maternal periconceptional UN from 60 days before until 30 days after mating on the ontogeny of placental @entity73087 enzyme activities. At day 85 of gestation, placental 11betaHSD-2 activity was lower in UN than in normally nourished (N) fetuses (P < .05) and was higher in twins than in singletons (P < .05). Furthermore, placental 11betaHSD-1 activity was not different between nutritional groups but was higher in twins than in singletons (P = .01). At day 85, fetal plasma @entity701 (P < .001) and @entity821 (P < .001) concentrations were lower in UN than in N fetuses, but the @entity701 to @entity821 ratio was higher in UN than in N fetuses (P = .01). There was no effect of fetus number on plasma @entity701 or @entity821 concentrations or on the ratio of @entity701 to @entity821 at day 85. Therefore, periconceptional UN and twinning may result in the alterations of placental 11betaHSD isozyme activities at particular times during gestation. Changes in these activities during critical periods of fetal development could affect transplacental transfer or placental generation of GCs that reach the fetus, potentially influencing the timing of activation of the fetal @entity2339 , fetal maturation, and hence the development and health later in life.
