Cadmium content of umbilical cord blood

Alteration of Mammary Gland Development and Gene Expression by In Utero Exposure to Cadmium

Environmental exposure to estrogens and estrogen like contaminants during early development is thought to contribute to the risk of developing breast cancer primarily due to an early onset of puberty; however, exposure during key developing windows may also influence the risk of developing the disease. The goal of this study was to ask whether in utero exposure to the metalloestrogen cadmium alters mammary gland development due to acceleration of puberty onset or to an effect on early development of the mammary gland. The results show that, in addition to advancing the onset of puberty, in utero exposure to the metalloestrogen cadmium altered mammary gland development prior to its effect on puberty onset. In utero exposure resulted in an expansion of the number of mammosphere-forming cells in the neonatal mammary gland and an increase in branching, epithelial cells, and density in the prepubertal mammary gland. In the postpubertal mammary gland, there was a further expansion of the mammary stem/progenitor cell population and overexpression of estrogen receptor-alpha (ERα) that was due to the overexpression and altered regulation of the ERα transcripts derived from exons O and OT in response to estradiol. These results suggest that in utero exposure to cadmium increases stem/progenitor cells, cell density, and expression of estrogen receptor-alpha that may contribute to the risk of developing breast cancer.

Distribution of Heavy Metals in the Liver of Foetuses and Female Mice after Oral Administration during Pregnancy - a Histochemical Study

The aim of this work was to study the distribution of heavy metals and of subsequently developed morphological changes in the liver of female mice and their foetuses after oral administration of high doses of lead, mercury, and cadmium (0.03 mg of metal per mouse and day). Heavy metals were administered to pregnant female mice on days 9-20 of pregnancy. The animals were euthanised by cervical dislocation. Samples of mother and foetal liver were subsequently collected and processed by means of the common technique for light and electron microscopy. Histochemical reaction based on metal conversion into appropriate sulphide that conjugates with silver was used for detection of heavy metals. Deposits of heavy metals were found at the periphery of lobules of the central vein in the liver of female mice. On the contrary, in the liver of foetuses no predilection site for localisation of the reaction product could be identified. At the electron microscopy level, accumulation of heavy metals was connected as a rule with the occurrence of certain damage to some organelles. Deposits of the reaction product were located mainly in hepatocytes and Kupffer cells. Heavy metals were bound to the heterochromatin of cell nuclei, as well as to some cytoplasmic organelles, such as rough endoplasmic reticulum, mitochondria, ribosomes, and lysosomes. The presence of heavy metals was associated with obliteration of cisternae of the rough endoplasmic reticulum, separation of ribosomes, and destruction of lysosomes. Vacuolation of cell cytoplasm was also a frequent phenomenon. An interesting finding was the "contrasting" of structures containing nucleic acids. Accumulation of metals in the liver of pregnant mice and their foetuses observed in our study indicated that placental barrier does not protect the foetal organism against penetration of metals. Their higher accumulation in foetal compared to maternal liver can be explained by the intense metabolism of differentiating hepatocytes.

Cadmium, lead, and selenium in cord blood and thyroid hormone status of newborns

Cadmium (Cd), lead (Pb), and selenium (Se) concentrations in cord whole blood, sampled from 24 women at the time of delivery in a hospital in Tokyo in 2005, were determined by inductively coupled plasma mass spectrometry with a reaction cell. Signal enhancement caused by nonspectroscopic interference for Se was evident and the standard addition technique was essential for correcting the interference. Median concentration in cord bloods was 0.20 ng/g, 6.7 ng/g (0.67 microg/dL), and 191 ng/g for Cd, Pb and Se, respectively. Lead concentration was lower, whereas Se concentration was higher, than those reported in other countries. The trace element concentration was related to the levels of thyroid stimulating hormone (TSH) and free thyroxin (fT4) in the neonatal blood sampled at 4-6 days postpartum. A significantly negative correlation was observed between Cd concentrations in cord blood and TSH concentration in neonatal blood. The result indicated the possible effect of in utero Cd exposure on thyroid hormone status of newborns and that Cd exposure level should be assessed as a covariate in the survey on the relationship between in utero chemicals (e.g., PCBs) exposure and thyroid hormone status.