Background:It was shown earlier that in women living in a polluted environment, the proportion of hypotrophic newborns was greater than in the general population. The placentas of these women show significant histological changes. The authors decided to check whether the activity of pyruvate kinase (PK), a key enzyme in the third stage of glycolysis, changes similarly.Material/Methods:The study was conducted on placentas collected from women who had lived in a polluted environment (Groups I and II) and those who had inhabited an unpolluted area (Group III) while pregnant. Total PK activity and the specific activities of its isoen­zymes were measured according to the Bücher and Pfleiderer method. The isolation of PK isoenzymes was carried out following the previously described procedure.Results:Total PK activity was lower in the placentas of women of Groups I and II than in those of Group III. The presence of two PK isoenzymes, M[sub]2[/sub] and L, was demonstrated. The M[sub]2[/sub] and L isoenzymes from the placentas of Groups I and II had a lower specific activity than those of Group III. Only one form of the M[sub]2[/sub] isoenzyme and the L dephospho-isoenzyme in the placentas from Groups I and II was observed, while in placentas of Group III women both forms of the M[sub]2[/sub] isoenzyme and the L phospho-isoenzyme were noted.Conclusions:It is possible that the presence of the two PK isoenzymes in the placenta ensures the production of a sufficient amount of pyruvate.

Keywords: Placenta - enzymology, Pyruvic Acid - metabolism, Air Pollution, Infant, Low Birth Weight, Infant, Newborn, Isoenzymes - metabolism, Placenta - enzymology, Poland, Pregnancy, Pyruvate Kinase - metabolism, Pyruvic Acid - metabolism