Research for the perinatal adaptation of fetus and newborn ; relation to apoptosis and growth factor

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Fetus and newborn show the many physiological and metabolic changes to adapt the dramatic environmental changes around the delivery. We investigated the hormones, growth factors and substances related to these changes.EGF increased fetal weight by controlling the amino acid transport in placenta. Retinol, insulin and insulin like growth factor also increased amino acid transport. EGF promoted the functional and morphological development of neonatal rat intestine and this change was inhibited by DL-α-difluoromethyl ornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC).Inhibition of polyamine synthesis by DFMO also induced intrauterine growth restriction. The depression of ODC activity in the placenta is the major factor of IUGR induced by DEMO administration, and polyatnines play important roles to carry pregnancy.We investigated heme metabolism in placenta. Transcription levels of the non-specific δ-aminolevulinate synthase and heme oxygenase-1 in placenta at the terminal stage of pregnancy were increased markedly and these enzymes were exclusively expressed in the trophoblast. Both enzymes were influenced by acute fetal hypoxia and suggest that placental heme metabolism is influenced by the oxygen supply.We established a sireptozotocin (STZ)-treated pregnant rat model with diabetes and signs and symptoms mimicking preeclampsia. This model closely is useful for basic study of the pathophysiology of pregnancy with diabetes.These data suggest that many hormones, growth factors and substances such as EGF, polyamine, insulin, retinoids which related to cell growth play some important roll during the perinatal period.