Publication details
Distribution of heavy metals in the kidney of foetus and mouse females after peroral administration during pregnancy - a histochemical study
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| Year of publication | 2009 |
| Type | Article in Proceedings |
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| Description | Objective of the study Toxicity of heavy metals and their influence on human and animal health was studied much time ago. Knowledge of penetration of heavy metals through the placenta to the embryo is very limited or quite is missing. Therefore we have decided to detect the distribution of heavy metals (which were administered to the pregnant females in food) in the kidneys of laboratory mouse foetuses and to determine possible sites of their cumulation with histochemical method. The results were compared with kidneys of mothers and control females fed standardly. Material and Methods Method described by Pearse (1972), based on conversion of metal on to specific sulphide which conjugates with silver, was used for metals detection. Experimental collection contained 40 pregnant females – 10 for control, 10 receiving by lead, 10 fed by mercury and 10 fed by cadmium in dose 0,03 mg of metal/mouse/day. Obtained tissue samples were processed by standard methods for purposes of light and electron microscopy. The histochemical reaction was performed on sections. Experiments with laboratory mouse were perfomed with permission in accordance to law term 311/1997 Sb. Results In light microscope, deposits of heavy metals cumulate in kidneys above all in proximal tubules and distal tubules. As compared with mother, reaction product in foetus was found in higher amount. At the level of electron microscopy, we have observed deposits of reaction product above all in nucleus, nucleolus of the cells of proximal and distal tubules, sporadically in cytoplasm. Deposits of reaction product were bound to rough endoplasmic reticulum, mitochondria and ribosomes. Cumulation of heavy metals as a rule was associeted with occurence of terminal damage of these organelles. Unexpected finding was „ contrasting“ of structures containing nucleic acids. Conclusions It is possible state, that the placenta does not function as a filtr barrier preventing penetration of heavy metals to the foetus. Kudney of the foetus even cumulate much more heavy metals than mother kidneys. Our observations confirm penetration of heavy metals through the biomembranes into the cell, where they affect morphology of the organels (dilatation and fragmentation of endoplasmic reticulum). In view of considerable cumulation in the nucleus, nucleolus and ribosomes, they can influence mechanism of the cell division and proteosynthesis. Occurence of reaction product in the apoptotic (necrotic) cell corroborates this hypothesis. Whether the cell death can be caused by heavy metals cumulation we cannot either acknowledge or refute. |