[Pheno-and genotyping of a placental detoxication system in ecologically unfavorable regions of Ukraine]. / Feno- i genotipirovanie dezintoksikatsionnoi sistemy platsenty v ékologicheski neblagopriiatnykh raionakh ukrainy.

During 1991-1993 period a study of detoxifying activity of the fetoplacental barrier and genotyping of the major detoxifying enzymes in it (CYP1A1 Ile462Val, GSTP1 Ile104Val, GSTM1 present/absent) was undertaken in different regions of Ukraine that were radioactively contaminated with summary effective equivalent annual expositional doses (SEEAED approximately 1.7 mSv (Group I) and 0.1-0.4 mSv (Group III), chemically polluted Zaporizzhia, monitored for ambient levels of benzo(a)pyrene (BP) (Group II) and Poltava that was judged as "clean" one (Group IV). Glutathione-S-transferase (GSTase) and glutathionereductase (GSSG-Rase) activities of cytosol and concentration of thiobarbituric acid reacting compounds (TBA-reactants) and reduced low-molecular weight thiols (rLMW thiols) were used as phenotype parameters. Cytosolic GSTase activities were nearly two times less in the samples from radioactively contaminated area (Group I, SEEAED approximately 1.7 mSv) and in chemically polluted area (Group II, mean BP level 12.3 ng/m3), compared with the groups III and IV. The highest level of TBA-reactants indicative of lipid peroxidation in response to radiation was observed in Group I, while the lowest level in Group IV. The level of rLMW thiols was 2.5-4 times more in Group II comparative with Groups I, III and IV. The frequency of the genotypes in all the investigated samples corresponds to that reported for Caucasians. For the combined exposure groups, individuals with the CYP1A1 (Ile462Val) genotype (n = 5) had significantly higher levels of GST, GSSG-R and TBA reacting compounds compared to individuals with the Ile462Ile genotype (n = 14 for TBA-reactants and n = 24--for GST and GSSG-R). Despite the challenge of small numbers of individuals, stratification by exposure group for Groups I, II and III indicated significantly higher GST levels in CYP1A1 (Ile462Val) variants from Groups II and III (n = 3) compared to the Ile462Ile variants (n = 17). The data demonstrate contributions by both exposure and genotype on the detoxification of radiation and chemical damage in the human placenta.

[Detoxicating function of the placenta of childbearing women from ecologically unfavorable regions of the Ukraine]. / Dezintoksykatsiina funktsiia platsenty u porodilei z ekolohichno nespryiatlyvykh raioniv Ukraïny.

A study of placental detoxifying activity was undertaken using as the investigated indices glutathione transferase and glutathione reductase activities and total amount of SH-groups and those of low-molecular weight thiols. Malonic dialdehyde content was used as a measure of lipid peroxidation. The placental samples were obtained in several regions of the Ukraine judged either "clean", chemically polluted or radioactively contaminated. In the samples from the "clean" region glutathione transferase and glutathione reductase activities as well as the total amount of SH-groups were higher than corresponding indices in ecologically unfavorable regions of the Ukraine. At radioactively heavily exposed women low glutathoione transferase activity combined with low content of SH-groups and pronounced increase of malonic dialdehyde. In the regions with the lower summary effective equivalent annual expositional doses the indices of placental glutathione status are more close to those characteristic for placenta from "clean" regions. The consequences of the more intensive but short exposure characteristic for the women evacuated from Pripyat on the second day after catastrophe were less manifest in the indices of the glutathione status. A decrease of glutathione transferase activity at chemically exposed women was in the range of the lowest values obtained for heavily radioactively exposed ones but differ by higher content of total SH-groups and low molecular weight thiols. The glutathione transferase activity of cytosol from the samples of chemically exposed women increased in vitro after their treatment with the reducing agent. More probable the different mechanisms underlie the similar reduce of glutahtione transferase activity in radioactively contaminated and chemically polluted regions of the Ukraine. The decreased activity of glutathione transferase activity in placenta correlated with the increased frequency of complications during the pregnancy and the delivery and with the worsening status of newborns.