[Rat alveolar type II injured by bleomycin].
OBJECTIVE
To explore dysfunction mechanism of rat alveolar type II (AT-II) injured by bleomycin (BLM).


METHODS
SD rats were injected with a single intratracheal dose of bleomycin or control saline. On day 7, 14, and 28 following intratracheal bleomycin or saline instillation, animals were killed under overdose of 1.5% sodium pentobarbital (0.25 ml/100 g, i.p.) and bronchoalveolar lavage fluid (BALF) from the lung was tested for the activity of pulmonary surfactant (PS) by the Whihelmy Film Balance. Several concentrations of bleomycin stimulated the culture of rat AT-II cells, and surfactant protein (SP) A, B, and aquaporin-1 (AQP) mRNA were analyzed by fluorescent quantitative polymerase chain reaction (FQ-PCR).


RESULTS
The activity of PS and hypoxemia significantly decreased on day 7 and improved on day 14 and completely recovered to normal status on day 28. SP-A, B, and AQP-1 mRNA expression in BLM-stimulated group were significantly lower than those in the control group (P<0.001).


CONCLUSIONS
BLM-injured AT-II cells decrease the levels of SP-A, B, and AQP-1 mRNA and cause PS dysfunction, resulting in hypoxemia and pneumonedema.
Kong
Lu
L
Laboratory of Cell Biochemistry, Beijing University of Chinese Medicine, Beijing 100029, China.
Wang
Zhi-gang
ZG
Niu
Jian-zhao
JZ
Wang
Ji-feng
JF
Jin
Huan
H
Yang
Mei-juan
MJ
Wang
Ling-qiao
LQ
Tang
Bing-hua
BH
Zhang
Qiu-ju
QJ
Tu
Heng-jing
HJ
D000818:Animals; D051398:Aquaporin 1 / Q000096:biosynthesis* / Q000235:genetics; D001761:Bleomycin / Q000008:administration & dosage / Q000633:toxicity*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D000860:Hypoxia / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D008297:Male; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000187:drug effects; D037662:Pulmonary Surfactant-Associated Protein A / Q000096:biosynthesis* / Q000235:genetics; D037701:Pulmonary Surfactant-Associated Protein B / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D037662:Pulmonary Surfactant-Associated Protein A; D037701:Pulmonary Surfactant-Associated Protein B; D012333:RNA, Messenger; D001761:Bleomycin; D051398:Aquaporin 1