Kalhan S C, D'Angelo L J, Savin S M, Adam P A
J Clin Invest. 1979 Mar;63(3):388-94. doi: 10.1172/JCI109314.
The effects of pregnancy and diabetes on systemic glucose production rates and the sources of glucose for the human fetus in utero were evaluated in five normal, four gestationally diabetic, and one insulin-dependent diabetic subject undergoing elective caesarean section at term gestation. Five normal nonpregnant women were studied for comparison. Systemic glucose production rates were measured with stable tracer [1-(13)C]glucose according to the prime-constant rate infusion technique. Even though the plasma glucose concentration during normal pregnancy had declined as compared with the nonpregnant subjects (P < 0.0005), the systemic glucose production rate was 16% greater, a rate sufficient to provide the glucose requirement of the fetus at term gestation. The decline in glucose concentration could be the result of an increase in apparent volume of distribution of glucose. Systemic glucose production rates in well-controlled, gestationally diabetic subjects were similar to those in normal pregnant subjects (2.07+/-0.53 vs. 2.42+/-0.51 mg/kg.min). The sources of glucose for the human fetus at term gestation were evaluated by comparing (a) natural variation in (13)C:(12)C ratio of plasma glucose and (b) enriched (13)C:(12)C ratio of plasma glucose during [1-(13)C]glucose infusion in maternal and fetal blood at delivery in both normal and diabetic subjects. These data showed that the fetal glucose pool was in equilibrium with the maternal glucose pool in both normal and diabetic subjects, indicating that a brief maternal fast did not initiate systemic glucose production in human fetus. A materno-fetal gradient was observed for betahydroxybutyrate.
对五名正常孕妇、四名妊娠期糖尿病患者和一名胰岛素依赖型糖尿病患者在足月妊娠时接受择期剖宫产手术的情况进行了评估，以研究妊娠和糖尿病对全身葡萄糖生成率以及子宫内人类胎儿葡萄糖来源的影响。选取了五名正常非孕妇作为对照进行研究。采用稳定示踪剂[1-(13)C]葡萄糖，根据初量-恒速输注技术测量全身葡萄糖生成率。尽管正常妊娠期间的血浆葡萄糖浓度与非妊娠受试者相比有所下降（P<0.0005），但全身葡萄糖生成率高出16%，这一速率足以满足足月妊娠胎儿的葡萄糖需求。葡萄糖浓度的下降可能是葡萄糖表观分布容积增加的结果。血糖控制良好的妊娠期糖尿病患者的全身葡萄糖生成率与正常妊娠受试者相似（2.07±0.53对2.42±0.51毫克/千克·分钟）。通过比较（a）正常和糖尿病受试者分娩时母体和胎儿血液中血浆葡萄糖的(13)C:(12)C比值的自然变化，以及（b）在输注[1-(13)C]葡萄糖期间血浆葡萄糖的富集(13)C:(12)C比值，评估了足月妊娠时人类胎儿的葡萄糖来源。这些数据表明，正常和糖尿病受试者的胎儿葡萄糖池与母体葡萄糖池处于平衡状态，这表明母体短暂禁食不会引发人类胎儿的全身葡萄糖生成。观察到β-羟基丁酸存在母胎梯度。
