Browsing by Subject "Clara cells"

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    Morphology and changes in Clara cells in the foetal bronchioles of Swiss mice
    (Murcia : F. Hernández, 1994) Blanco, A.; Mendez, A.; Carrasco, L.; Bautista, María José; Sierra, M. A.
    In this work we have studied the morphology and evolution of Clara cells in the bronchiolar mucosa of lungs from 63 Swiss mice foetuses that were classified into three groups according to age (14, 16 and 18 days). A control group composed of 21 15-day-old Swiss mice was also studied. The most salient feature of the Clara cells observed was the occurrence of two types of secretory granules and a large smooth endoplasmic reticulum . On the other hand, the Clara cells of the control group had a single secretory granule. Clara cells thus seem to take part in bronchiolar metabolism, as they were quite abundant in the early foetal groups and diminished as birth approached. This cell decrease was confirmed by the control group (15- day-old mice), the bronchioles of which contained scant cells and numerous ciliated cells.
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    Pulmonary response to methylcyclopentadienyl manganese tricarbonyl treatment in rats: injury and repair evaluation
    (Murcia : F. Hernández, 2006) Halatek, T.; Opalska, B.; Rydzynski, K.; Bernard, A.
    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.