Effects of bleomycin and Staphylococcus protein-A on lungs of mice.

Fibrosis of organs and tissues are major causes of morbidity and mortality in human. The currently available pharmacologically based treatments are unsatisfactory. As an experimental animal model antitumor antibiotic drug bleomycin (BLM) is widely used to produce lung fibrosis. The present study has been undertaken to investigate the possible role of a potent immunomodulator Staphylococcus protein-A (SpA) in the modulation of lung lesions caused by treatment of BLM. In mice BLM, 0.5 mg in 200 microliters of normal saline and SpA, 6 micrograms in 200 microliters of normal saline was administered singly or in combination twice a week for 4 weeks. The fibrotic lesions in the lungs were observed after 4 weeks of BLM treatment. After 4 weeks treatment of SpA, the hyperreactive changes in bronchi and bronchioles were observed. In the co-treatment group of BLM and SpA, the effects observed were in the form of enhanced lesions in the lung parenchyma. Moreover, the pleural lesions were also observed in co-treatment group (BLM + SpA). Opposite to the assumption, SpA being a potent immunomodulator was not able to reduce the lung lesions produced by BLM.

Histomorphological changes in lung of rats following exposure to wood smoke.

Rats were exposed to repeated, intermittent exposure to smoke generated from combustion of 1g wood/15 min, total period for 75 min daily under dynamic exposure conditions, over a period of 15, 30 and 45 days. First 15 days exposure caused mild bronchiolitis, hyperplasia and hypertrophy of bronchiolar epithelial lining cells, some necrosed lining cells desquamated into lumens, congestion of parenchymatous blood vessels, oedema, hyperplasia of lymphoid follicles, peribronchiolar and perivascular infiltration of polymorphonuclear cells, and mild emphysema. These lesions progressed further during 30 and 45 days of exposure, though emphysematous changes remain constant. By 30 days and 45 days, hyperplastic and hypertrophic changes of bronchioles become quite marked, with mononuclear cells infiltration and alveolar septa thickening. Hematological studies show marginal alterations in hemoglobin levels, ESR, PCV and TLCS during 15 days, where as significant changes in eosinophil were observed during 30 and 45 days, and ESR during 45 days only. The results indicate progressive pathomorphological pulmonary lesions with subsequent exposure to wood smoke in controlled conditions.