title: Glycolytic enzymes of human fetal and neonatal intraocular fluids.
abstract: The levels of the glycolytic enzymes, phosphohexose isomerase, aldolase and LDH and its isozymes, were ascertained in the aqueous of human stillbirths and premature neonate dead (19-24 weeks gestation) and compared with those of older neonates (28-41 weeks) of low survival due mainly to respiratory failure. The fetal aqueous displayed a much greater LDH-P level (mean mU/ml +/- SEM: 45,600 +/- 2550; 72 eyes) in contrast to the near-term infant value (2420 +/- 615; 27 eyes) and 8-20 times higher aldolase and phosphohexose isomerase levels. LDH-P of the fetal vitreous was much lower (5820 +/- 860 mU/ml; 25 eyes) and for lens employed as a filtered homogenate in saline (1:20), amounted to 52.2 +/- 4.2 mU/mg lens (24 eyes). The distribution of LDH isozymes in the fetal vitreous and lens homogenate and the near-term neonate aqueous as determined by polyacrylamide disc electrophoresis, was similar to that of the fetal aqueous, LDH-1 and LDH-5 being least and LDH-3 and LDH-4, the highest. A few small but significant differences were apparent as compared to the fetal aqueous isozymes and included decrements in vitreous LDH-4, lens LDH-3 and neonatal aqueous LDH-3 and increases in vitreous LDH-2 and near-term aqueous LDH-4. The current findings may have application to retinoblastoma for which higher aqueous LDH levels have been reported and employed as a diagnostic adjunct. However, the fetal aqueous LDH values far exceed those encountered in this embryonal-type tumour.
mesh_terms: D001082:Aqueous Humor / Q000201:enzymology; D001826:Body Fluids / Q000201:enzymology*; D005123:Eye / Q000201:enzymology*; D005260:Female; D005313:Fetal Death / Q000201:enzymology; D005333:Fetus / Q000378:metabolism*; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism; D005956:Glucose-6-Phosphate Isomerase / Q000378:metabolism; D006019:Glycolysis; D006801:Humans; D007231:Infant, Newborn; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007908:Lens, Crystalline / Q000201:enzymology; D011247:Pregnancy; D014018:Tissue Distribution; D014822:Vitreous Body / Q000201:enzymology
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D005634:Fructose-Bisphosphate Aldolase; D005956:Glucose-6-Phosphate Isomerase