Expression of nitric oxide synthase, aquaporin 1 and aquaporin 5 in rat after bleomycin inhalation.
OBJECTIVE
Nitric oxide (NO) and aquaporins (AQPs) are believed to play an important role in the pathogenesis of pulmonary inflammation and edema. The aim of this study was to investigate the role of NO synthase (NOS) and AQP in acute lung injury (ALI) lung following bleomycin inhalation in rats.


METHODS
A prospective controlled trial in a university research laboratory.


METHODS
Sprague-Dawley rats were treated by inhalation of 10 U/kg bleomycin hydrochloride in 5 ml of normal saline. Control rats were treated with 5 ml normal saline alone. The animals (6-8 rats per group) were killed on days 4, 7 or 14.


RESULTS
We analyzed the change in expression of inducible NOS (iNOS), neuronal NOS (nNOS), endothelial NOS (eNOS), aquaporin 1 (AQP1) and aquaporin 5 (AQP5) over time by Western blot. Nitrate and nitrite concentrations were measured in bronchoalveolar lavage fluid (BALF) using a modified Griess reaction. The nitrite and nitrate concentrations in BALF from rats 4 days after bleomycin exposure were greater than those from saline-treated rats. Immunoblotting studies demonstrated increased levels of eNOS in the rat lung at 4, 7 and 14 days and iNOS at 7 and 14 days after bleomycin inhalation. However, nNOS expression was unaltered. Although AQP1 expression was decreased in rats at 4 days, AQP5 expression was increased at 4, 7 and 14 days.


CONCLUSIONS
This study demonstrates that NO metabolites increase along with eNOS and iNOS expression during the acute exudative phase in ALI, and that AQP and NOS are regulated independently in bleomycin-induced pulmonary edema.
Jang
An-Soo
AS
Department of Internal Medicine, Soonchunhyang University Hospital, 1174 Jung-dong, Wonmi-gu, Bucheon-si, 420-767 Gyeonggi-do, Republic of Korea. jas877@schbc.ac.kr
Lee
Jong-Un
JU
Choi
Inseon-S
IS
Park
Kyung-Ok
KO
Lee
June Hyuk
JH
Park
Sung-Woo
SW
Park
Choon-Sik
CS
D000818:Animals; D051398:Aquaporin 1; D051402:Aquaporin 5; D020346:Aquaporins / Q000378:metabolism*; D001761:Bleomycin; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D011654:Pulmonary Edema / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012128:Respiratory Distress Syndrome / Q000378:metabolism* / Q000473:pathology; D018709:Statistics, Nonparametric
C496022:Aqp1 protein, rat; C496040:Aqp5 protein, rat; D051402:Aquaporin 5; D020346:Aquaporins; D008565:Membrane Proteins; D001761:Bleomycin; D051398:Aquaporin 1; D019001:Nitric Oxide Synthase