18 research outputs found
Pulmonary response to methylcyclopentadienyl manganese tricarbonyl treatment in rats: injury and repair evaluation
Methylcyclopentadienyl manganese
tricarbonyl (MMT), an organometallic compound, used
as an antiknock additive in fuels, may produce alveolar
inflammation and bronchiolar cell injury.
The aim of the experimental study on female rats
was to determine by morphological examination and
sensitive biomarkers, the course of the injury and repair
process following a single i.p. injection of 5 mg/kg
MMT. The animals were sacrificed 12, 24, 48 hours or 7
days post-exposure (PE). The first biochemical changes
12 h PE showed an increase in GSH-S-transferase (GST)
activity in the lung parallel to the earliest observed
morphological changes -vacuolation and swollen
cytoplasm in type I pneumocytes. Alterations in type I
pneumocytes were most prevalent in rat lung 24 h PE.
Clara cells with dilated smooth endoplasmic reticulum
membranes and cytoplasmic vacuolation could be
observed. Compared to the values found for controls,
Clara cell protein (CC16) in the bronchoalveolar lavage
fluid (BALF) at 24 and 48 h PE decreased by 58% and
55%, respectively. At the same time (at 24 and 48 h), the
total protein concentration in BALF increased 5 and 7
times, respectively. A significant rise in hyaluronic acid
(HA) level was observed 24 and 48 h PE. Divided type
II pneumocyte cells and Clara cells in their mitotic phase
were observed in immunocytochemistry (detecting BrdU
binding into DNA) 48 h PE. Seven days after MMT
administration, fibroblasts, macrophages, collagen and
elastin fibres could be seen in the alveolar walls as well
as neutrophils, lymphocytes, and alveoli macrophages in
the alveolar lumen. We conclude that injury and repair of
bronchial epithelium cells, especially of Clara cells and
type II pneumocyte cells, play an important part in MMT toxicity, probably depending on the antioxidant status of
these cells. The sensitive biomarkers of CC16 and
hyaluronic acid in BALF and serum reflect lung injury
and indicate the time course of pulmonary damage and
repair processes
Lung permeability, antioxidant status, and NO2 inhalation: A selenium supplementation study in rats
Little is known about antioxidant status, selenium status in particular, and lung response to NO2, which acts as a proinflammatory air pollutant. The effects of a low selenium diet (1.3 mu g Se/d) with or without selenium supplementation were therefore studied in 128 Wistar rats, 2 mo old, male exposed to either acute (50 ppm, 30 min), intermittent subacute (5 ppm, 6 h/d, 5 d), intermittent long-term NO2 (1 ppm, 10 ppm, 6 h/d, 5 d/wk, 28 d), or normal atmospheric air (controls). Following sacrifice, measurements of lipid peroxidation ( thiobarbituric acid-reactive substances, chemiluminescence), antioxidative protective enzymes (glutathione peroxidase [GPx], superoxide dismutase [SOD], glutathione S-transferase [GST], ceruloplasmin), lung damage ( lactate dehydrogenase, alkaline and acid phosphatases), lung permeability ( total protein, albumin), and inflammation (cell populations), along with the determination of new biomarkers such as CC16 (Clara-cell protein), were performed in serum and bronchoalveolar lavage fluid (BALF). While selenium-supplemented animals had increased GPx activity in serum prior to inhalation experiments, they also had decreased BALF CC16, blood SOD, and GST levels. Nevertheless, the protective role of normal selenium status with respect to NO2 lung toxicity was evident both for long-term and acute exposures, as the increase in BALF total proteins and corresponding decrease in serum (indicating increased lung permeability) was significantly more pronounced in selenium-deficient animals. During the various inhalation experiments, serum CC16 demonstrated its key role as an early marker of increased lung permeability. These findings corroborate the important role of selenium status in NO2 oxidative damage modulation, but also indicate, in view of its negative impact on CC16, a natural anti-inflammatory and immunosuppressor, that caution should be used prior to advocating selenium supplementation
Lung permeability, antioxidant status, and NO2 inhalation: A selenium supplementation study in rats
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Fate and effects of nanoparticles in aquatic ecotoxicity tests
Contains fulltext :
75500.pdf (publisher's version ) (Open Access)10 p
The safety of medical devices containing DEHP plasticized PVC or other plasticizers on neonates and other groups possibly at risk (2015 update)
status: publishe