모체 Thyroxine 투여가 태아알코올효과를 가진 흰쥐 대뇌겉질 및 해마에서 NPY 함유 신경세포의 생후 발달에 미치는 영향

Abstract

Maternal alcohol abuse is considered to be one of the most prominent cause of neurobiological malformations in the postnatal and adult life of the offspring. In this study, the author investigated the effects of maternal alcohol drinking on the postnatal development of Neuropeptide-Y(NPY)-containing neuron, and, the influence of thyroxine treatment on the cerebral cortex and hippocampus of pups of alcohol abused mother. Time-pregnant rats were divided into three groups. Alcohol-fed group A(n = 4) received 35 calories of liquid alcohol diet daily from gestation day 6; control pair-fed group B(n = 4) was fed a liquid diet in dextrin replaced alcohol isocalorically; alcohol + T_(4) group C(n = 4) received 35 calories liquid alcohol diet and exogenous thyroxine (5㎍/kg/day) subcutaneously. After the pups were born, the pups of each were fostered by surrogate mother. Alcohol + T_(4) group showed prominent NPY immunoreactivity in the cerebral cortex compared to alcohol and control pair-fed group at P7. In alcohol + T_(4) group, NPY-containing neurons were found widely distribution in the all layers of cerebral cortex after P14. Also, numerical decrease of NPY-containing neuron was not found according to increasing age in alcohol + T_(4) group. However, the decrease of NPY-containing neuron was clearly observed in alcohol group compared to alcohol + T_(4) group after P14. In hippocampus, control pair-fed and alcohol + T_(4) group were appeared similar patterns after P7. However, in alcohol + T_(4). the intensity of NPY immunoreactivity was stronger in alcohlol + T_(4) group as compared to the control pair-fed group, In addition, in alcohlol + T_(4) group, NPY immunoreactivity was prominent appeared in CA2 and CA3 at P14 as compared to the control pair-fed group. The present results showing the increase of intensity and number of NPY-containing neurons in cerebral cortex and hippocampus of pups of exogenous T_(4) supplemented alcohol-exposed dams as compared to control pair-fed and alcohol-exposed pups at P7, presumably suggest that NPY-containing neurons might be regulated by the early postnatal growth stimulatory effect of the exogenously supplemented T_(4). Therefore, the increase of NPY synthesis caused by maternal administration of exogenous thyroxine may ameliorate fetal alcohol effects, one of the ill effects as a result of the dysthyroid state following maternal alcohol abuse.