Coulter C L, Young I R, Simonetta G, McMillen I C
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Am J Physiol. 1993 Aug;265(2 Pt 1):E203-9. doi: 10.1152/ajpendo.1993.265.2.E203.
The aim of this study was to determine the effect of fetal hypophysectomy on the plasma concentrations of catecholamines and enkephalins in the fetal sheep between 120 and 140 days gestation under basal and hypoxic conditions. During basal conditions, there was no difference in the plasma concentrations of norepinephrine and epinephrine between intact and hypophysectomized groups. Fetal plasma norepinephrine concentrations were significantly increased during hypoxia in intact fetal sheep (7.2 +/- 2.2 pmol/ml, -15 min; 20.2 +/- 7.7 pmol/ml, 30 min) between 130 and 140 days, but after fetal hypophysectomy there was no significant norepinephrine response to hypoxia at this gestational age (4.7 +/- 1.3 pmol/ml, -15 min; 8.8 +/- 2.8 pmol/ml, 30 min). In contrast, fetal plasma epinephrine concentrations were significantly increased during hypoxia in both the intact (1.5 +/- 0.5 pmol/ml, -15 min; 3.3 +/- 1.7 pmol/ml, 30 min) and hypophysectomized groups (1.8 +/- 0.6 pmol/ml, -15 min; 6.8 +/- 4.1 pmol/ml, 30 min) between 130 and 140 days. During basal conditions, plasma concentrations of free Met-Enk were significantly less in hypophysectomized fetal sheep (170.8 +/- 34.3 pg/ml; 120-140 days) than in intact fetal sheep (305.6 +/- 47.3 pg/ml). There were no differences, however, in the fetal plasma concentrations of total Met-Enk between the intact (18.0 +/- 1.9 ng/ml) and hypophysectomized (16.9 +/- 2.6 ng/ml) groups. During hypoxia, there were no changes in the fetal plasma concentrations of either free or total Met-Enk in the intact or hypophysectomized groups.(ABSTRACT TRUNCATED AT 250 WORDS)
本研究的目的是确定在基础状态和低氧条件下，胎羊垂体切除对妊娠120至140天胎羊血浆儿茶酚胺和脑啡肽浓度的影响。在基础状态下，完整组和垂体切除组之间去甲肾上腺素和肾上腺素的血浆浓度没有差异。在妊娠130至140天期间，完整胎羊在低氧时血浆去甲肾上腺素浓度显著升高（-15分钟时为7.2±2.2 pmol/ml；30分钟时为20.2±7.7 pmol/ml），但在该孕周进行胎羊垂体切除后，对低氧没有明显的去甲肾上腺素反应（-15分钟时为4.7±1.3 pmol/ml；30分钟时为8.8±2.8 pmol/ml）。相比之下，在妊娠130至140天期间，完整组（-15分钟时为1.5±0.5 pmol/ml；30分钟时为3.3±1.7 pmol/ml）和垂体切除组（-15分钟时为1.8±0.6 pmol/ml；30分钟时为6.8±4.1 pmol/ml）在低氧时胎羊血浆肾上腺素浓度均显著升高。在基础状态下，垂体切除胎羊（妊娠120 - 140天）血浆游离甲硫氨酸脑啡肽浓度（170.8±34.3 pg/ml）显著低于完整胎羊（305.6±47.3 pg/ml）。然而，完整组（18.0±1.9 ng/ml）和垂体切除组（16.9±2.6 ng/ml）之间胎羊血浆总甲硫氨酸脑啡肽浓度没有差异。在低氧期间，完整组或垂体切除组胎羊血浆游离或总甲硫氨酸脑啡肽浓度均无变化。（摘要截短于250字）
