Absence of an Additional Fibrotic Response Caused by Oxygen in the Lungs of Rats After the Intratracheal Administration of Bleomycin

Abstract

Bleomycin 0.4, 0.6, 1.0 or 3.5 mg/kg body weight was administered via the trachea in rats. After various time intervals some of the animals were exposed to 50% oxygen for either 4 or 24 h. The rats were then sacrificed at different times. Control rats remained untreated or received physiological saline. Lung histology was studied by light microscopy. In a number of rats the lung content of hydroxyproline was determined. Mild reactions, namely increases in pneumocytes type II and macrophages, oedema and prefibrotic alterations were observed after the instillation of bleomycin. The reactions were comparable to those observed after additional hyperoxia alone. Lung hydroxyproline concentration was not increased after bleomycin plus oxygen as compared with bleomycin alone. We conclude that no added toxicity is caused by 50% oxygen supplied for 4 or 24 h subsequent to doses of bleomycin that lead to mild pulmonary abnormalities in the absence of hyperoxia.

Moxibustion Has a Positive Effect on Pulmonary Fibrosis: An Alternative Approach

“…Bleomycin-induced pulmonary fibrosis is a globally accepted animal model due to its high successful rate and close to the pathophysiology of human IPF (Fireman et al 2001, Giri et al 1980, Veninga et al 1988). Rats in blank group (n=17), model group (n=15), moxibustion group (n=16), and prednisone group (n=15) were analyzed.…”

Anaesthesia and anti-cancer chemotherapeutic drugs

“…In animal models, hyperoxia exposure shortly after bleomycin administration synergistically increases its pulmonary toxicity [26][27][28]. In contrast, delayed exposure is not harmful [29][30][31][32][33].…”