metallothionein and Birth-Weight

Experiments were designed to evaluate and compare metallothionein (MT), zinc and cadmium levels in human placentas of smoking and non-smoking women. Smoking was assessed by self-reported cigarette consumption and urine cotinine levels before delivery. Smoking pregnant women with urine cotinine levels higher than 130 ng/ml were included in the smoking group. Determination of placental MT was performed by western blot analysis after tissue homogenization and saturation with cadmium chloride (1000 ppm). Metallothionein was analyzed with a monoclonal antibody raised against MT-1 and MT-2 and with a second anti mouse antibody conjugated to alkaline phosphatase. Zinc and cadmium were determined by neutron activation analysis and atomic absorption spectrometry respectively. Smokers showed higher placental MT and cadmium levels, together with decreased newborn birth weights, as compared to non-smokers. The semi-quantitative analysis of western blots by band densitometry indicated that darker bands corresponded to MT present in smokers' samples. This study confirms that cigarette smoking increases cadmium accumulation in placental tissue and suggests that this element has a stimulatory effect on placental MT production.

Topics: Adult; Birth Weight; Blotting, Western; Cadmium; Cotinine; Female; Humans; In Vitro Techniques; Infant, Newborn; Maternal-Fetal Exchange; Metallothionein; Placenta; Pregnancy; Smoking; Zinc

Intrauterine growth restriction (IUGR) is a pleiotropic complication of pregnancy. Prematurity and growth abnormalities are common risk factors for perinatal morbidity and mortality. Free radical damage has been recognized as a common pathogenic mechanism of many neonatal diseases. The aim of the present study was to characterize the possible links between the level of maturity, the birthweight and the antioxidant status of neonates born with IUGR. Our data suggest that the stress markers measured on the cord blood of neonates with IUGR and mature, healthy neonates do not necessarily reflect the extent of oxidative stress. However, significant correlations were found between the maturity of the neonates with IUGR and the oxidative damage. The mature IUGRs exhibited ONOO(-) accumulation and increased lipid peroxidation more frequently as compared with the pre-term group. The results suggest that the oxidative injury in IUGR may depend on the level of maturity and the birthweight.

Topics: Birth Weight; Catalase; Erythrocytes; Female; Fetal Blood; Fetal Growth Retardation; Heme Oxygenase (Decyclizing); Humans; Hydrogen Peroxide; Infant, Newborn; Male; Metallothionein; Oxidation-Reduction; Peroxynitrous Acid; RNA, Messenger; Superoxide Dismutase

Cadmium (Cd) is a widespread, highly toxic environmental pollutant known to accumulate in human placenta. The aim of the present study was to elucidate to what extent the accumulation of Cd in human placenta interacts with the transport of micronutrients to the fetus. Cd and micronutrients were measured in placenta and umbilical cord blood from 44 non-smoking, rural Bangladeshi women, using ICPMS. Metallothionein (MT) protein expression was determined in placenta using Western blot. Cd in placenta (median 110 microg/kg dry weight, 20 microg/kg wet weight) was positively associated with maternal urinary Cd. It was also positively associated with Cd in umbilical cord blood (median 0.16 microg/kg), but negatively associated with zinc (Zn; median 3mg/kg) in umbilical cord blood. Umbilical cord blood Zn was positively associated with birth anthropometry measures, and the Cd-related impairment of Zn in umbilical cord blood seemed to decrease size at birth. In multivariate analysis, MT protein expression was associated with Cd (positively) in placenta, but not with Zn or copper (Cu) in placenta. In conclusion, the Cd concentrations in placenta were clearly elevated, which seemed to impair Zn transfer to the fetus. Induction of MT explained the placental accumulation of Cd, but not the impairment of Zn transport.

Topics: Adult; Birth Weight; Cadmium; Environmental Pollutants; Female; Fetus; Humans; Male; Metallothionein; Micronutrients; Placenta; Pregnancy; Young Adult

This study was designed to assess the effect of Cadmium (Cd) and lead (Pb) exposure during pregnancy in rats and their correlation with metallothionein (MT). Rats were exposed to either 10 ppm Cd or 300 ppm Pb through drinking water during pregnancy. Both metals were measured in placenta, fetus brain and fetal and maternal blood. MT was quantified in placenta and fetus brain and it was also observed in placenta by immunohistochemical technique. Offspring weight was found to be significantly lower for the Cd exposure group than for the control group. A Cd increase in the placenta of the exposed group was accompanied by MT induction; these effects were related to a limited accumulation of Cd in fetus brain. In contrast, dam Pb exposure caused an accumulation of Pb in the fetus brain and induced damage to placenta. The results account for differences in the transference of these metals during pregnancy that could be related to their toxicity.

Topics: Administration, Oral; Animals; Birth Weight; Blood; Brain; Cadmium; Calibration; Cattle; Dose-Response Relationship, Drug; Female; Fetus; Immunohistochemistry; Lead; Maternal-Fetal Exchange; Metallothionein; Placenta; Pregnancy; Quality Control; Rats; Reference Standards; Spectrophotometry, Atomic

This study is designed to determine the placental zinc (Zn) and cadmium (Cd) levels in mothers who were smokers, mothers who were thought to be exposed to air pollution, and mothers who were non-smokers and to investigate the relationship between the expression of placental metallothionein (MT) binding these metals and blood progesterone level. Placental Zn and Cd levels were measured by atomic absorption spectrometry. Presence of placental MT was determined immunohistochemically. Placental changes were examined by light microscope after H&E and PAS staining. Immunohistochemical MT staining of syncytiotrophoblastic and villous interstitial cells were scored as positive or negative. Among the 92 mothers included in the study, 33 were smokers (Group I), 29 had been exposed to air pollution (Group II) and 30 were non-smoker rural residents who had never been exposed to air pollution (Group III). Mean off-spring birth weight of 3198.62+/-380.01 g and mean placenta weight of 561.38+/-111.55 g of Group II were lower when compared with those of other two groups. In Group I, mean placental Cd and Zn were 0.063+/-0.022 microg/g and 39.84+/-15.5 microg/g, respectively, being higher than in other groups. In Group II, mean placental Cd and Zn levels were higher than those of Group III. Blood progesterone levels of subjects in Group I (121 ng/ml) were the lowest of all groups. While the mean count of villi was the highest in Group III; the highest mean count of syncytial knots was in Group II. Thickening of vasculo-syncytial membrane was most prominent in Group I. Similarly, MT staining was positive and very dense in 72.7% (24/33) of cases in Group I (p

Topics: Adult; Age Factors; Air Pollution; Birth Weight; Cadmium; Female; Humans; Immunohistochemistry; Infant, Newborn; Male; Maternal Age; Maternal-Fetal Exchange; Metallothionein; Microscopy, Polarization; Organ Size; Placenta; Pregnancy; Progesterone; Smoking; Spectrophotometry, Atomic; Zinc

Ethanol, under certain conditions, alters the metabolism of sulfur amino acids, metallothionein (MT) and zinc. If chronic ethanol administration during pregnancy decreases the availability of sulfur amino acids or Zn, this deficiency could contribute to growth retardation of the fetuses, one of the features of fetal alcohol syndrome. The purpose of this study was to discern whether chronic ethanol administration to pregnant rats alters glutathione (GSH), MT or Zn content of selected tissues of the dams and fetuses. Sprague-Dawley rats were fed from gestational days 5 to 19 either the control diet ad libitum (AF), the ethanol diet ad libitum (EF) or the control diet using the pair-feeding technique (PF). On the 19th day of gestation, total hepatic GSH was significantly lower for the EF and PF dams than for the AF dams. Hepatic MT contents were similar for the AF and EF dams, and hepatic MT content was significantly greater for the PF dams than the AF and EF dams. The three groups did not differ regarding hepatic Zn content of dams or fetuses. In summary, on the 19th day of gestation, chronic ethanol feeding of pregnant rats did not lower the maternal hepatic GSH level below that of PF dams, did not induce hepatic MT in the dams and did not prevent fetuses from achieving body weights and hepatic Zn concentrations equal to those of controls.

Topics: Animals; Birth Weight; Body Weight; Ethanol; Female; Fetal Alcohol Spectrum Disorders; Fetal Growth Retardation; Fetus; Glutathione; Litter Size; Liver; Metallothionein; Organ Size; Pregnancy; Pregnancy, Animal; Rats; Rats, Inbred Strains; Zinc