[Effects of high dose ambroxol on lung injury induced by paraquat in rats].
OBJECTIVE
To evaluate the protective effect of high dose ambroxol, a mucoactive drug, on acute lung injury caused by paraquat in rats.


METHODS
One hundred and thirty-six healthy male Sprague-Dawley rats were randomly divided into three groups: control group (n = 24) injected with normal saline intraperitoneally, PQ group (n = 56) [(2% paraquat (25 mg/kg) injected into peritoneal cavity on the first day)] and AT group (n = 56) ambroxol 35 mg/kg was injected into peritoneum daily after paraquat intoxication once daily for 7 consecutive days. The arterial gas was determined and the extent of lung injury was assessed by measuring the ratio of wet to dry weight (W/D) and protein content in BALF, the WBC count, the percentage of PMN, the content of malondialdehyde (MDA) and the levels of superoxide dismutase (SOD) in the blood and BALF respectively. Left lung tissue was observed through both light microscope and electron microscope (TEM).


RESULTS
The white cell count and the content of protein in the blood and the BALF of PQ group were significantly higher than those of the control group (P < 0.05 or P < 0.01). On the 7th day, the content of MDA 9 [(8.12 +/- 1.12) nmol/ml] in the serum of PQ group was significantly higher than the control group and the GSH-Px activity [(1256.8 +/- 133.2) U/ml] was significantly lower than the control group (P < 0.01). The white cell count and the content of protein in the blood and the BALF of AT group were significantly lower than the PQ group (P < 0.05 or P < 0.01). On the 7th day, the content of MDA in the serum of the AT group [(4.86 +/- 0.75) nmol/ml] was significantly lower than the PQ group and the GSH-Px activity [(1509.5 +/- 183.0) U/ml] and the SOD activity [(3903.2 +/- 374.7) U/ml] were significantly higher than the PQ group (P < 0.01). Under optical and electronic microscopes, the injury of lung tissue was reduced after large dose of ambroxol was administered.


CONCLUSIONS
Treatment with ambroxol (35 mg/kg) could influence the status of oxidative stress in lung and alleviate lung injury induced by paraquat. Ambroxol has obviously therapeutic effect on paraquat poisoning.
Ma
Yu-teng
YT
Department of Emergency, the Second Affiliated Hospital of Hebei Medical University, Shijiazhuang 050000, China.
Tian
Ying-ping
YP
Shi
Han-wen
HW
Lv
Cui-huan
CH
Liu
Jian-hui
JH
Sun
Zhi-ping
ZP
D055371:Acute Lung Injury / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000551:Ambroxol / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D004195:Disease Models, Animal; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D018384:Oxidative Stress; D010269:Paraquat / Q000506:poisoning*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000551:Ambroxol; D010269:Paraquat