Rolph T P, Jones C T
J Dev Physiol. 1983 Feb;5(1):31-49.
Functional glycolytic capacity and its regulation have been studied in the fetal guinea-pig heart during O2 deprivation in situ and in the Langendorff perfused heart. Anaerobic glycolytic flux, at 2 mumol/min per g wet wt. was similar in the 48-50 and 60-65 days fetal and adult guinea-pig heart, despite lower fetal phosphofructokinase activity. During O2 deprivation in situ and in the perfused heart glucose was the major substrate, with glycogen making a smaller contribution. Glycolytic capacity became more tightly regulated during fetal heart development. Thus at 48-50 days glycolysis was increased during O2 deprivation by substrate supply, but at 60-65 days activation of phosphofructokinase was required also. Low malate/aspartate cycle activity in the fetal heart was suggested by the absence of an increase in malate and alanine at the expense of aspartate. The large proportion of aerobic glycolytic flux converted to lactate concurred with this. Because of the low O2 consumption and relatively high aerobic glycolytic flux, the proportion of glycolytically-derived ATP was 3-4 fold higher in the fetal than adult heart, and may explain its functional resistance to O2 deprivation.
在原位缺氧以及Langendorff灌流心脏的条件下，对胎豚鼠心脏的功能性糖酵解能力及其调节进行了研究。在48 - 50日龄以及60 - 65日龄的胎豚鼠心脏和成年豚鼠心脏中，无氧糖酵解通量相似，为每克湿重2 μmol/分钟，尽管胎儿的磷酸果糖激酶活性较低。在原位缺氧以及灌流心脏过程中，葡萄糖是主要底物，糖原的贡献较小。在胎儿心脏发育过程中，糖酵解能力的调节变得更加严格。因此，在48 - 50日龄时，缺氧期间糖酵解通过底物供应增加，但在60 - 65日龄时，还需要磷酸果糖激酶的激活。胎儿心脏中苹果酸/天冬氨酸循环活性较低，这是由于苹果酸和丙氨酸没有以天冬氨酸为代价增加而表明的。大量的有氧糖酵解通量转化为乳酸也与此相符。由于低氧消耗和相对较高的有氧糖酵解通量，胎儿心脏中糖酵解衍生的ATP比例比成年心脏高3 - 4倍，这可能解释了其对缺氧的功能抗性。
