UNDIFFERENTIATED ENZYMIC COMPOSITION OF HUMAN FETAL LUNG AND PULMONARY TUMORS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 37  (3) , 884-891
Abstract
The concentrations of 16-21 enzymes, representing various metabolic pathways, were determined in human adult, fetal and neoplastic lung. At midgestation, 12 enzymes (among them, several that metabolize amino acids) were above their adult values while 3 other enzymes were still at low concentrations. These signs of biochemical immaturity are contrasted and compared with those in fetal human liver and rat lung. The enzymic composition of the 11 human pulmonary tumors studied resembled that of normal fetal lungs. The same 12 enzymes were elevated and the same 2 were decreased (compared to nonneoplastic adult lung) in both. The characteristic abnormality in the overall pattern of enzymes, the concentrations of individual ones and the quality of pyrroline-5-carboxylate reductase was evident in primary and metastatic tumors. The mean concentrations of 10 enzymes in the tumors were significantly different (higher or lower) from those in control lungs (P < 0.001 to < 0.05). The best markers of neoplasticity were thymidine kinase, peptidyl proline hydroxylase, phosphoserine phosphatase, hexokinase and pyrroline-5-carboxylate reductase. Quantification of a small battery of enzymes, none of them tissue specific, can distinguish adult human lung from its neoplasms.