[A rat model of pulmonary fibrosis induced by infusing bleomycin quickly through tracheal intubation].
OBJECTIVE
To study the approach for developing a rat model of pulmonary fibrosis induced by bleomycin (BLM).


METHODS
Different doses (7, 6, 5, 3.4, 2, 1 mg/kg) of bleomycin A5-saline were infused into the rats' lung in bleomycin-treated group through tracheal intubation, and rats in sham-operated group were infused with same volume of saline. The living state and lung pathology of the rats were observed. The author deeply studied the condition of the rats in 1 mg/kg bleomycin-treated group, and the changes of body weight and lung pathology were observed. Lung quotient, the content of transforming growth factor beta1(TGF-beta1) and platelet-derived growth factor (PDGF) in serum were measured on the 14th, 28th and 45th day of the experiment.


RESULTS
The study demonstrated that infusing large doses of bleomycin A5 quickly through tracheal intubation had a high mortality, and infusing 1 mg/kg quickly could successfully develop an animal model of pulmonary fibrosis. Compared with the sham-operated group, fibrosis was appeared obviously in the rats' lung in 1 mg/kg bleomycin A5-treated group after 14 days of experiment, diffuse fibrosis was appeared after 28 days of experiment, and the fibrosis became more severe after 45 days of experiment. The body weight of the rats in bleomycin-treated group was declined after 3, 7 and 14 days of experiment as compared with the sham-operated group (P<0.01). Twenty-one days after the experiment, the body weight was declined too, but there was no significant difference between the bleomycin-treated group and the sham-operated group (P>0.05). Lung quotient was increased 14, 28 and 45 days after the experiment (P<0.01), the level of serum TGF-beta1 began to increase since 28 days after the experiment (P<0.05, P<0.01), and the level of serum PDGF also increased gradually 45 days after the experiment (P<0.05). And the mortality rate of 1 mg/kg bleomycin A5-treated group was lower than those of the other doses of bleomycin A5-treated groups.


CONCLUSIONS
A rat model of pulmonary fibrosis can be duplicated successfully by infusing 1 mg/kg bleomycin A5 quickly through tracheal intubation.
Zhang
Wei
W
Department of Respiratory Diseases, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing 100700, China.
Lu
Xiang-Feng
XF
Zhang
Xiao-Mei
XM
Wu
Jian-Jun
JJ
Jiang
Liang-Duo
LD
D000818:Animals; D001761:Bleomycin / Q000008:administration & dosage; D004195:Disease Models, Animal; D007442:Intubation, Intratracheal; D008168:Lung / Q000473:pathology; D008297:Male; D011658:Pulmonary Fibrosis / Q000139:chemically induced*; D051381:Rats; D017208:Rats, Wistar
D001761:Bleomycin