Exposure to nanoparticles of magnetite Fe3O4 in three different doses and their influence on selected respiratory parameters of bronchoalveolar lavage after intravenous instillation.

OBJECTIVES: Due to nano-dimensions (less than 100 nm), can nanoparticles probably penetrate through various membranes and travel from the bloodstream to other organs in the body. The aim of our study was to find out whether NPs Fe3O4 (coated with sodium oleate) injected into the tail vein of laboratory Wistar rats pass through the bloodstream to the respiratory tract (in comparison with a control group); and if so whether increasing doses of NPs Fe3O4 have an escalating harmful effect on selected bronchoalveolar lavage (BAL) parameters. METHODS: Wistar rats were intravenously given 3 doses of the suspension of NPs Fe3O4 (0.1% LD50 = 0.0364, 1.0% = 0.364 and 10.0% = 3.64 mg/kg animal body weight). Seven days later, we sacrificed the animals under anaesthesia, performed bronchoalveolar lavage (BAL), and isolated the collected cells. Many inflammatory and cytotoxic BAL parameters were examined. RESULTS: Both inflammatory and cytotoxic BAL parameters affected by Fe3O4 suspension were changed compared to control results, but not all were statistically significant. Thus, the NPs Fe3O4 passed through the bloodstream to the respiratory tract and affected it. The highest concentration of NPs Fe3O4 (10%) had the most influence on BAL parameters (7 of 12 parameters). Only 3 parameters showed a pure dose dependence. CONCLUSION: We assume that the adverse effect of Fe3O4 NPs in our study is probably not correlated with the dose, but rather with the size of the particles or with their surface area.

Combined effect of selected mineral fibres and tobacco smoke on respiratory tract in rats.

The rats were inhaling amosite and wollastonite fibres at two concentrations (30 and 60 mg/m3) one hour every second day and cigarette smoke of 3 cigarettes per day (with the exception of Saturdays and Sundays). They were sacrificed after 6 month of exposure. Bronchoalveolar lavage (BAL) was performed and selected inflammatory and cytotoxic parameters were examined. Amosite: inflammatory parameters were the most changed after 60 mg/m3 in both groups with or without smoking; the cytotoxic parameters were strongly influenced by smoking. Wollastonite (asbestos substitute) inhalation confirmed lower inflammatory and cytotoxic effects on all examined animal groups in comparison with amosite.

Effect of TiO2 nanofibres on selected bronchoalveolar parameters in acute and subacute phase--experimental study.

Titanium dioxide nanofibres (TiO2) were intratracheally instilled in dose of 4 mg/0.2 mL saline solution per animal (Wistar rats). After 48 hours and 14 days the animals were exsanguinated (under i.p. thiopental narcosis), bronchoalveolar lavage (BAL) was perfomed and cells from BAL fluid were isolated. Following inflammatory, cytotoxic and oxidative stress BAL parameters were examined: differential cell count (% of alveolar macrophages (AM), polymorphonuclears and lymphocytes); the viability and phagocytic activity of AM; the proportion of immature cells; the proportion of multinucleated cells; count of AM/mL lavage; count of BAL cells/mL lavage; the level of ascorbic acid and activity of superoxide dismutase, both in tissue homogenate and in bronchoalveolar lavage fluid. The majority of examined BAL parameters in the acute and subacute phase in our study suggest serious inflammatory and cytotoxic processes in lung after exposure to TiO2.

The influence of cigarette smoke on the selected bronchoalveolar cells in experiment.

UNLABELLED: The occurence of lung diseases (obstructive, malignant) resulting from smoking has an increasing tendency. The lung is the primary organ at risk from the effects of inhaled cigarette smoke and smoking has been implicated as a contributing factor to the causation of various respiratory diseases. The aim of presented work was to find out the subchronic effect of the 6-month exposure to cigarette smoke on the selected inflammatory and cytotoxic parameters of bronchoalveolar lavage in W rats and thus to contribute to understanding of the mechanism of action of tobacco smoke and/or path mechanism of lung injury developed after cigarette smoking. In special chamber, the animals smoked 8 standard research 1R1 type of cigarettes per day, except Saturdays and Sundays, during 6 months. The daily concentration of total particulate matter (TPM)/m3 air for two hours per exposure requiring to burn eight cigarettes was 85 mg. Animals were sacrificed after the 6-month exposure and bronchoalveolar lavage (BAL) was performed and selected inflammatory and cytotoxic BAL parameters were examined and compared with the control group. Following BAL parameters were investigated: the total cell and alveolar macrophages (AM) count in BAL, the differential cell count (% of AM, % of polymorphonuclears--PMN, % of lymphocytes--Ly), proportion of immature AM, proportion of bi-nucleated cells--BNC, viability, the phagocytic activity of AM, cytokines TNF-alpha (tumor necrosis factor alpha) and IL-1beta (interleukin-1beta). CONCLUSION: A) The 6-month smoking of eight cigarettes daily significantly changed prevailing number of examined BAL parameters; B) The presence of inflammatory and cytotoxic responses in lung tissue can probably signalize beginning or developing of disease process.

Inflammatory and haematotoxic potential of indoor Stachybotrys chartarum (Ehrenb.) Hughes metabolites.

Mould Stachybotrys chartarum (Ehrenb.) Hughes is known to pose a health risk in indoor environments. Most of its strains can produce several intra- and extracellular trichothecene mycotoxins. Complex secondary metabolites of stachybotrys isolates from mouldy dwellings/public buildings in Slovakia were intratracheally instilled in Wistar male rats (4 microg in 0.2 mL of 0.2 % dimethylsulphoxide; diacetoxyscirpenol as the positive control). After three days, haematological parameters were measured in peripheral blood and inflammatory response biomarkers in bronchoalveolar lavage fluid (BALF), and the results were statistically analysed. Exometabolites proved to suppress red blood cell (RBC), decreasing the total RBC count, haemoglobin, and haematocrit. The exposed rats showed significantly higher total BALF cell count, indicating inflammation, lower alveolar macrophage counts, and increased granulocyte count related to the BALF cells. Due to haematotoxic and inflammation-inducing properties, metabolites of S. chartarum can cause damage to the airways and haematological disorders in occupants of mouldy buildings.

Protective effect of melatonin in acetic acid induced colitis in rats.

Possible protective effects of exogenous melatonin on colonic inflammation were studied in rats. Colitis was induced by intracolonic (i.c.) instillation of 4% acetic acid (AA) and the resulting injury was assessed after 1 and 48 hr. Diffuse hyperemia and bleeding with erosions and ulcerations were observed in the colons of vehicle-treated rats. Melatonin administered in doses of 5 and 10 mg/kg reduced significantly the extent of gross mucosal damage after intraperitoneal as well as i.c. dosing. The inflammation induced increase in colonic wet weight was also reduced by melatonin treatment. In the early phase of colonic inflammation (60 min), melatonin partly prevented the decrease of reduced glutathione (GSH) content and limited lysosomal enzyme, N-acetyl-glucosaminidase and cathepsin D, activities induced by AA, with no changes in proteins or acid phosphatase activity. Increase of myeloperoxidase activity (MPO) caused by colonic inflammation was prevented by melatonin given i.c. As observed 48 hr after AA exposure, there was no difference between the effect of vehicle and melatonin on the content of GSH. Colitis did not influence the melatonin content of the colon. After administration of exogenous melatonin, plasma, pineal and gut melatonin tended to increase. The results indicate that melatonin participates in various defense mechanisms against colonic inflammatory processes by preserving the important endogenous antioxidant reserve of GSH, by preventing lysosomal enzyme disruption, by inhibiting enhanced MPO activity, thus reducing the extent of colonic damage, mainly in the early phase of colitis.

Effect of exposure to ceramic fibres and cigarette smoke on antioxidant status of the lung.

OBJECTIVES: The programmes of asbestos replacement brought the need to use other fibres for insulation or reinforcement of material. The aim of the presented study was to follow the effect of refractory ceramic fibres (RCF3) alone or in combination with cigarette smoke (CS) on antioxidant status of the lung in experiment on animals. As free radicals are supposed to play a role in pathogenesis of lung diseases and the toxicity of particles has been associated with production of reactive oxygen species, the antioxidant status may serve as marker of lung injury. Our hypothesis was that the effect of combined exposure to RCF3 and CS will be additive or synergic. DESIGN: Scheme of experiment: Wistar rats were randomly divided into 4 groups per 6 animals: control, intratracheal exposure to 4 mg of RCF3, inhalatory exposure to mainstream of cigarette smoke from 8 standard research 1R1 cigarettes per day, and both intratracheal exposure to RCF3 and inhalatory to CS. The exposure lasted 6 months, the inhalatory exposure was performed 5 times per week. After finishing the exposure bronchoalveolar lavage of lungs was performed and ascorbic acid, superoxide dismutase, glutathione and glutathione peroxidase were determined in lung tissue and cell free fraction of bronchoalveolar lavage fluid (BALF). RESULTS: The results showed that the most sensitive indicator of changes in antioxidant status was glutathione, which was changed in all groups both in BALF and lung tissue homogenate.

Pulmonary cytotoxicity of secondary metabolites of Stachybotrys chartarum (Ehrenb.) Hughes.

Damp dwellings represent suitable conditions for extended indoor moulds. A cellulolytic micromycete Stachybotrys chartarum (Ehrenb.) Hughes is considered to be a tertiary colonizer of surfaces in affected buildings. Known adverse health effects of S. chartarum result from its toxins--trichothecenes or atranones, as well as spirolactams. Mechanism of their potential pathological effects on the respiratory tract has not yet been sufficiently clarified. The cytotoxic effects of complex chloroform-extractable endo- (in biomass) and exometabolites (in cultivation medium) of an indoor S. chartarum isolate of an atranone chemotype, grown on a liquid medium with yeast extract and sucrose at 25 degrees C for 14 d, on lung tissue were evaluated in the 3-day experiment. For the purpose, 4 mg of toxicants were intratracheally instilled in 200 g Wistar male rats. A trichothecene mycotoxin diacetoxyscirpenol was used as the positive control. Bronchoalveolar lavage (BAL) parameters--viability and phagocytic activity of alveolar macrophages (AM), activity of lactate dehydrogenase, acid phosphatase and cathepsin D in cell-free BAL fluid (BALF), as well as in BAL cells, were measured. Acute exposure to the metabolites caused statistically significant changes, indicating lung tissue injury in the experimental animals. Decreased AM viability and increased activity of lysosomal enzyme cathepsin D in BAL cells after fungal exometabolite exposure were the most impressive. As toxic principles were found predominantly in the growth medium, toxins were more likely responsible for lung cell damage than e.g. fungal cell wall components. S. chartarum toxic metabolites can contribute to the ill health of occupants of mouldy building after inhalation of contaminated aerosol.

Influence of refractory ceramic fibres - asbestos substitute - on the selected parameters of bronchoalveolar lavage 6 months after intratracheal instillation to W-rats.

Industrial fibrous dusts are applied in many industrial branches and represent adverse factors in occupational and environmental area. Refractory ceramic fibers (RCFs) - amorphous alumina silicates - are used as one kind of asbestos substitutes. Because RCFs are relatively durable and some RCFs are respirable, they may present a potential health hazard by inhalation. The aim of present work was to find out the subchronic effect of RCFs on selected parameters of bronchoalveolar lavage (BAL) in W-rats, confirm the biopersistence of RCFs after 6 month instillation and contribute to the understanding of the pathomechanism of lung injury after fibrous dust exposure. Wistar rats were intratracheally instilled with 4 mg/animal of RCFs - exposed group and with 0.4 ml saline solution/animal - control group. Animals were sacrificed after 6 month exposure. Bronchoalveolar lavage (BAL) was performed and selected BAL parameters (mainly inflammatory and cytotoxic) were examined. After treatment with RCFs the following changes were observed: statistically significant increase in proportion of lymphocytes and polymorphonuclears as well as in % of immature alveolar macrophages (AM) and phagocytic activity of AM; statistically significant decrease in viability of AM and proportion of AM (from the differential cell count) in comparison with the control group. The results of this study indicated that RCFs even 6 months after intratracheal instillation very significantly changed the majority of examined BAL parameters. The presence of inflammatory and cytotoxic response in lung may signalize beginning or developing disease process.

Effect of intratracheal fibres exposure on the rat lung.

The changes in antioxidant status of rat lung after intratracheal instillation of stone-wool and glass fibres were studied. The animals were exposed to 2 or 8 mg of fibres for 4 or 16 weeks, the bronchoalveolar lavage was performed and the activity of superoxide dismutase, glutathione peroxidase and the total amount of glutathione was estimated both in tissue and in cell free fraction of bronchoalveolar lavage and the ascorbic acid was determined in lung tissue. The results showed the higher burden by stone-wool. Most changes were detected in groups exposed to higher dose of fibres for shorter time period, the most sensitive parameter was superoxide dismutase. The lung tissue was studied also by light microscopy and transmission electron microscopy.

Lung cytotoxicity of combined exposure to refractory ceramic fibres and cigarette smoke.

Changes in some lung cytotoxic parameters after exposure to refractory ceramic fibres (RCF) or to cigarette smoke (S) and after combined exposure to RCF+S were studied in male Wistar rats in order to evaluate their potential adverse health effects. Four groups of rats were treated as follows : 1) intratracheally instilled by saline solution (0.4 ml); 2) intratracheally instilled by 4 mg of RCF; 3) exposed only to S (85 mg of total particulate matter/m(3) air ) for two hours daily; 4) exposed to RCF+S. After 6 months the animals were exsanguinated and the bronchoalveolar lavage (BAL) was perfomed. Viability and phagocytic activity of alveolar macrophages (AM), activity of lactate dehydrogenase (LDH) in cell-free BAL fluid (cf-BALF), acid phosphatase (ACP) and cathepsin D (CATD) in cfBALF, in BALF cells and in the lung tissue were estimated. Viability of AM was depressed by every type of exposure with RCF+S effect being at least additive. Phagocytic activity of AM increased in the presence of RCF. No significant changes in LDH activity were found. Activities of lysosomal enzymes measured in the lung tissue homogenates were not significantly changed, but those in the cfBALF increased especially after exposure to S with most expressive increase in BALF cells after exposure to S and RCF+S. In the case of CATD the effect of RCF+S was more than additive. The results point out to the persistence of the RCF exposure cytotoxic effects and their amplification by cigarette smoke.