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1
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Effect of acute and chronic lead exposure on the level of sulphydryl groups in rat brain

100%
Dabrowska-Bouta B., Struzynska L., Rafalowska U.
Acta Neurobiologiae Experimentalis
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1996
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vol. 56
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issue 1
233-236
EN
Lead is known to be a potent neurotoxic agent. The interactions of lead with proteins are considered to be at least one of the mechanisms due to which lead exerts its toxicity. In the present work we demonstrate that acute and chronic models of exposure to lead affected the level of total and protein-bound SH groups in homogenates and synaptosomes obtainded from rat brains. The concentrations of SH groups were lowered significantly (P less then 0.05) in both types of poisoning. Different classes of cellural proteins were considered to play a role in high affinity binding of lead to these ligands.
2
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Acute lead toxicity and energy metabolism in rat brain synaptosomes

51%
Struzynska L., Dabrowska-Bouta B., Rafalowska U.
Acta Neurobiologiae Experimentalis
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1997
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vol. 57
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issue 4
275-281
EN
Although the neurotoxic effects of lead (Pb) are well documented, the subcellular mechanisms of its action in the central nervous system are not fully understood. The present work examined some parameters of energy metabolism in nerve endings of the brains of adult rats exposed to Pb. We applied the model of acute Pb toxicity in vivo, imitating the acute action of lead observed in occupationally exposed workers or in occasional incidents of poisoning. The measurement of Pb levels in the synaptosomal fraction exhibited its significant accumulation under applied conditions. Oxygen consumption increased in synaptosomes from Pb treated rats whereas the activity of cytochrome c oxidase did not change. The intrasynaptosomal levels of ATP and CrP were significantly elevated, as was the activity of creatine kinase, suggesting the activation of the CrP/CK system. On the other hand, the activity of the synaptosomal Na+,K+ ATP ase decreased. We suggest that under acute Pb toxicity conditions the mobiliaztion of CrP/CK system may take place to protect the cell against the effects of decreased Na+,K+ ATP ase activity. ATP ase
3

The occurrence of total and labile forms of lead and nickel in the sediments of the port of Gdansk

51%
Radke B., Dembska G., Aftanas B., Bolalek J.
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EN
Sediment samples collected in 1997 and 1998 from the Wislane, Obroncow Poczty Polskiej or Siarkowe (Sulfur), Oliwskie and Paliw Plynnych (Liquid Fuels) quays were sorted into four grain size fractions, i.e., <2.00 mm; 2.00 - 0.063 mm; 0.063 - 0.032 mm; <0.032 mm. It was determined that the sediments in the port area are small-grained sands with a small admixture of silt. The analyzed benthic sediments contained different amounts of organic matter and displayed varying water content. The mean contents of the labile form of lead and its total concentration in the grain size fraction <2.00 mm were 6.4 mg.kg ?1 d.w. and 11.4 mg.kg ?1 d.w., respectively. These values for nickel were 2.9 mg.kg ?1 d.w. for the labile form and 7.1 mg.kg ?1 d.w. for total concentration. The widest range of values was noted in the sediment surface layer (0-20 cm) for total concentration and labile forms. Sediments collected from locations close to the Gulf of Gdansk (e.g., Liquid Fuels Quay) and from areas with low industrial activity (e.g., Sulfur Quay) exhibited Pb and Ni concentrations which were many times lower than those in other areas of the port which were investigated.
4
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Is lead toxicosis a reflection of altered energy metabolism in brain synaptosomes ?

51%
Rafalowska U., Struzynska L., Dabrowska-Bouta B., Lenkiewicz A.
Acta Neurobiologiae Experimentalis
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1996
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vol. 56
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issue 2
611-617
EN
RThe aim of the experiment presented here was to discern whether prolonged consumption of leaden water, that imitates environmental exposure, affects some energetic parameters in nerve endings of adult rat brain.Our results indicated that during chronic lead intoxication the oxidation chain of synaptic mitochondria remains intact.The oxygen consumption by synaptosomes and activity of cytochrom oxidase in synaptic and pericarionic mitochondria obtained from intoxicated rats did not change in comparison to those from the conrtol samples.Compared with the control samples, the concentration of ATP decreased and the concentration of creatine phosphate (CrP) increased drasticly in fractions obtained from Pb2+ intoxicated animals with simultaneously increased activity of creatine kinase (CK).It seems likely that, the CrP/Cr/CK system constituens a satisfactory regulatory mechanism for chronic Pb2+ toxicity on energy metabolism in nerve endings of the adult rats.
5

Phospholipid content and lamellar structures in the epididymal epithelial cells of rats treated chronically with lead acetate [Pb(II)]

51%
Wiszniewska B., Marchlewicz M., Piasecka M., Wenda-Rozewicka L., Swider-Al-Amawi M.
Folia Biologica
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1998
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vol. 46
215-224
EN
The electron-microscopic observations accomplished covered epididymal epithelial cells of rats receiving lead acetate for five times longer than the duration of one spermatogenesis. These cells were found to possess a large number of vacuoles and conglomerates containing plicated membranes or tightly packed myelin-like lamellar formations. Further observations also revealed the formation of lamellar structures in mitochondria, dilatation of cisternae in the Golgi apparatus, and increased phagocytosis of spermatozoa by epithelial cells. The presence of a large amount of membranous material correlated with the increased content of phospholipids in epididymal epithelial cells. It may be suggested that the presence of such a great quantity of lamellar structures in epididymal epithelial cells of rats treated chronically with lead is the result of several processes, including the augmented synthesis of membranes associated with encircling the deposits of lead, autophagy in the cells, as well as intensified phagocytosis of spermatozoa.
6
Content available remote

Effects of lead on cholinergic SN56 neuroblastoma cells

45%
Jankowska-Kulawy A., Gul-Hinc S., Bielarczyk H., Suszkiw J. B., Pawelczyk T., Dys A., Szutowicz A.
Acta Neurobiologiae Experimentalis
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2008
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vol. 68
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issue 4
453-462
EN
Age-dependent accumulation of lead in brain has been implicated in the pathomechanisms of Alzheimer.s disease. The aim of this work was to investigate whether cholinotoxic effects of lead may result from alterations in acetyl-CoA metabolism. One day exposure of differentiated SN56 cholinergic neuroblastoma cells to 0.5 mumol/L lead or 0.01 mmol/L amyloid-beta1-42 increased fraction of nonviable cells to about 20%. Suppression of choline acetyltransferase activity occurred only in the presence of fresh amyloid-beta1-42, whereas lead was ineffective. All agents in combination caused suppression of acetyl-CoA in cytoplasm and mitochondria down to 19% and 34% of controls, respectively. Inverse correlation was observed between whole cell acetyl-CoA level and fraction of nonviable cells at different combinations of lead and other neurotoxic compounds. It indicates that lead had no primary suppressive effect on cholinergic phenotype but, at least in part, exerted cytotoxic influence on cholinergic neurons through the decrease of their acetyl-CoA.
7

Zn and Pb concentration in seminal plasma in reference to selected parameters of semiological assessment of bull semen

45%
Janicki B., Cygan-Szczegielniak D.
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EN
The Zn and Pb concentration was determined in 45 samples of bull semen from three Artificial Insemination Stations (A,B,C) differing in degree of environmental pollution. Bull semen was diluted with Biociphos-Plus to such an extent as to obtain 16 million sperm cells in an insemination dose. The research aimed at assessing the correlation between zinc, lead and other parameters influencing the semiological assessment of bull semen. The content of zinc and lead was determined with the use of the flame method and an absorption spectrophotometer (AAS). Positive, statistically significant correlations between zinc concentration and semen motility were observed in station A at r = 0,61 and station C at r = 0,614. In station B these correspondences were not statistically confirmed. Positive correlation at r = 0,583 was observed in case of zinc and the ejaculate volume only in station B. No statistically significant correlation was observed between lead concentration and the analyzed parameters.
8

The effect of cadmium and lead ions on microbial decomposition of organic biopolimers in an eutropic lake

45%
Gajewski A. J., Chrost R. J.
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issue 3
71-81
EN
The effects of cadmium and lead ions on bacterial ectoenzymatic activities and on the rates of organic substrates uptake were investigated in short-period experments.Both the acivitiees of ectoenzymes and rates of organic substrates uptake by bacteria were strongly inhibited by studied metal ions even in their low concentrations.Three types of inhibition: competitive (aminopeptidase) ,noncompetitive (lipase) and mixed (alkaline phosphatse) due to Pb and Cd ions were observed.The potential mechanisms of changes of the physical and chemical properties of studied enzymes by cadmium and lead were discussed.
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