Plasma epinephrine appearance and clearance rates in fetal and newborn sheep.
Plasma epinephrine appearance and clearance rates in fetal and newborn sheep.
复制标题
DOI：
10.1152/ajpregu.1993.265.4.r756
复制
发表时间：
1993-10
期刊：
影响因子：
--
通讯作者：
H. Stein;K. Oyama;A. Martinez;B. Chappell;J. Padbury
中科院分区：
文献类型：
--
作者：
H. Stein;K. Oyama;A. Martinez;B. Chappell;J. Padbury
新生儿血浆儿茶酚胺水平升高相比，胎儿的生命。这是否反映了出生后儿茶酚胺分泌增加或清除率降低尚不清楚。为了确定血浆中的外观和清除率的儿茶酚胺过渡到出生后的生活，我们比较了血浆肾上腺素的外观和清除率在胎羊出生前和分娩后的新生儿。在妊娠127 +/- 1天时和剖腹产后妊娠130 +/-1天时，通过放射性示踪剂分析测量8个胎儿的血浆肾上腺素出现率和清除率。在胎儿（26 +/- 4 ng.kg-1 x min-1）或新生儿研究（31 +/- 5 ng.kg-1 x min-1）期间，血浆肾上腺素出现率无差异。胎儿血浆肾上腺素清除率（131 +/- 13 ml.kg-1 x min-1）显著高于新生儿血浆肾上腺素清除率（40 +/- 3 ml.kg-1 x min-1）。因此，胎儿血浆肾上腺素的出现率是没有不同的出现率在立即新生儿时期时，儿茶酚胺水平高于在大多数其他生理情况。出生时循环中儿茶酚胺水平的增加部分是由于清除率的显著降低。胎盘对全身清除的贡献可能是胎儿和新生儿清除率差异的主要原因。
Newborn plasma catecholamine levels are elevated compared to fetal life. Whether this reflects increased catecholamine secretion after birth or decreased clearance is not known. To determine the plasma appearance and clearance rates for catecholamines during the transition to postnatal life, we compared plasma epinephrine appearance and clearance rates in fetal sheep before birth and in newborns after delivery. Plasma epinephrine appearance and clearance rates were measured by radiotracer analysis in eight fetuses at 127 +/- 1 days of gestation and, after cesarean delivery, at 130 +/- 1 days of gestation. There was no difference in plasma epinephrine appearance rate during the fetal (26 +/- 4 ng.kg-1 x min-1) or newborn studies (31 +/- 5 ng.kg-1 x min-1). The fetal plasma epinephrine clearance rate (131 +/- 13 ml.kg-1 x min-1) was significantly higher than newborn plasma epinephrine clearance rate (40 +/- 3 ml.kg-1 x min-1). Thus fetal plasma epinephrine appearance rate is not different from appearance rate in the immediate newborn period when catecholamine levels are higher than during most other physiological circumstances. The increase in circulating catecholamine levels at birth is due in part to a significant decrease in clearance rate. It is likely that removal of the placental contribution to whole body clearance accounts for much of the difference observed in fetal and newborn clearance rates.