Rosenkrantz T S, Knox I, Zalneraitis E L, Raye J R, Porte P J, Cramer R, Smoloski R, Phillipps A F
Department of Pediatrics, University of Connecticut Health Center, Farmington 06030.
Am J Physiol. 1993 Dec;265(6 Pt 2):R1262-9. doi: 10.1152/ajpregu.1993.265.6.R1262.
Previous studies in the fetal lamb have demonstrated that hyperglycemia stimulates the fetal metabolic rate. The present study examined the effects of chronic fetal hyperglycemia on fetal cerebral metabolic rate and electrocortical activity. Nine chronically instrumented fetal lambs had measurements of cerebral blood flow and cerebral uptake/excretion of oxygen, glucose, lactate, and beta-hydroxybutyrate taken before and during a 48-h fetal glucose infusion. Electrocortical activity was also recorded. The fetal arterial glucose concentration was 19.8 +/- 2.0 mg/dl before glucose infusion and 48 +/- 4.5 to 54.6 +/- 6.6 mg/dl during the infusion period. Cerebral blood flow and cerebral glucose and oxygen uptake increased by 219, 209, and 171%, respectively, by the end of the infusion period. There was a linear relationship between the fetal arterial glucose concentration and cerebral blood flow and cerebral glucose and oxygen uptakes. The electroencephalogram showed significant slowing with increases in the cerebral metabolic rate. These findings suggest that fetal hyperglycemia is associated with significant metabolic stimulation of the brain.
先前对胎羊的研究表明，高血糖会刺激胎儿代谢率。本研究考察了慢性胎儿高血糖对胎儿脑代谢率和皮层电活动的影响。9只长期植入仪器的胎羊在48小时胎儿葡萄糖输注前和输注期间测量了脑血流量以及脑对氧气、葡萄糖、乳酸和β-羟基丁酸的摄取/排泄情况。还记录了皮层电活动。胎儿动脉葡萄糖浓度在葡萄糖输注前为19.8±2.0毫克/分升，在输注期间为48±4.5至54.6±6.6毫克/分升。到输注期结束时，脑血流量以及脑葡萄糖和氧气摄取分别增加了219%、209%和171%。胎儿动脉葡萄糖浓度与脑血流量以及脑葡萄糖和氧气摄取之间存在线性关系。脑电图显示随着脑代谢率增加出现显著减慢。这些发现表明，胎儿高血糖与脑的显著代谢刺激有关。
