Pathophysiology of fetal hypoxia with special reference to fetal sympathoadrenal system and its clinical evaluation

1.分别于择期剖宫产、正常分娩和异常分娩时检测母血、胎儿血、羊水和胎儿尿中左旋多巴、多巴胺、去甲肾上腺素、肾上腺素和DOPAC的浓度。获得了以下结果。(1)胎儿交感肾上腺系统不依赖于母体。(2)分娩时坐位对胎儿的压力较仰卧位小。(3)羊水中儿茶酚胺浓度可作为评价胎儿应激的一个良好指标。(4)羊水中的多巴胺由胎儿肾脏循环中的左旋多巴产生，经胎儿泌尿系统大量分泌，经胎膜单胺氧化酶代谢.本实验通过测定胎鼠脑组织中腺嘌呤核苷酸、葡萄糖、乳酸和儿茶酚胺的含量，探讨了胎鼠缺氧后脑组织生化紊乱作为脑组织损伤的一个致病因素。结果如下。(1)胎儿缺氧后，脑组织ATP和葡萄糖含量明显降低，并伴有乳酸的减少。(2)在胎儿缺氧前母体给予葡萄糖对预防缺氧诱导的脑功能障碍具有有利的作用，在缺氧期间维持脑中的高能量状态。(3)胎儿脑组织中大量存在去甲肾上腺素和多巴胺。

1. The concentrations of L-dopa, dopamine, norepinephrine, epinephrine and DOPAC were examined in maternal blood, fetal blood, amniotic fluid and fetal urine at the time of elective cesarean section, normal delivery and abnormal delivery with fetal stress. The following results were obtained. (1) the fetal sympathoadrenal system was independent of the mother. (2) Sitting position of delivery was less stressful to the fetus during delivery compared with supine position of delivery. (3) Catecholamine concentrations in amniotic fluid may be a good indicator to assess the fetal stress. (4) Dopamine in amniotic fluid was produced in fetal kidney from circulating L-dopa and secreted adundantly via fetal urinary system and metabolized by monoamine oxidase in fetal membrane.2. Animal experiments were performed to investigate the biochemical disorders of brain following fetal hypozia as a causative factor of brain tissue injury, by measuring adenine nucleotides, glucose, lactate and catecholamines in fetal rat brain. The results were as follows. (1) Brain tissue ATP and glucose contents were markedly reduced with an accumu-lation of lactic acid following fetal hypoxia. (2) The maternal administration of glucose before fetal hypoxia has a favorable effect to prevent hypoxia-induced brain disorder, maintaining a high energy state in the brain during hypoxia. (3) Norepinephrine and dopamine existed in large amonut in fetal brain tissue.