[Protective effect of limb ischemic preconditioning on acute lung injury induced by lipopolysaccharide in rats].
OBJECTIVE
To explore the protective effect of noninvasive limb ischemic preconditioning (N-LIP) on acute lung injury (ALT) induced by lipopolysaccharide (LPS) in rats.


METHODS
Fifteen female SD rats were randomly divided into a control group, an acute lung injury group (ALI group), an acute lung injury and noninvasive limb ischemic preconditioning group (ALI+N-LIP group). After ALI rats were treated with N-LIP, the changes of airway resistance (AR) and dynamic compliance (Cdyn) were tested by invasive pulmonary function system and recorded. Blood samples and bronchoalveolar lavage fluid (BALF) were collected, the amounts of white blood cell (WBC) in BALF were counted by cytometry, and the level of lactate dehydrogenase (LDH) in BALF was also examined by automatic biochemistry analyzer. The level of serum superoxide dismutase (SOD) and malondialdehyd (MDA) was examined by chromatometry. The lung tissues were acquired to observe the expression of pulmonary surfactant-associated protein-A (SP-A) and pathological changes.


RESULTS
After being stimulated by methacholine (Mch), the increasing rate of AR and decreasing rate of Cdyn in the ALI+N-LIP group were less than those in the ALI group (P<0.01). The levels of WBC and LDH in BALF in the ALI+N-LIP group were much lower than those in the ALI group (P<0.05). Meanwhile, the activity of serum SOD in the ALI+N-LIP group was higher, and the level of serum MDA was lower than that in the ALI group (P<0.05). The expression of SP-A in the lung tissue in the ALI+N-LIP group was the highest in the 3 groups, while that in the ALI group was the weakest (P<0.01). Injury of the lung tissue in the ALI+N-LIP group was less than that in the ALI group, but more severe than that in the control group.


CONCLUSIONS
N-LIP has protective effect on acute lung injury induced by LPS in rats. The possible mechanism is related to improving the secretion of SP-A and antioxidation.
Third Department of General Surgery, Third Xiangya Hospital, Central South University, Changsha 410013.
Zhi
Z
Song
Wanjun
W
Luo
Ling
L
Qin
Shengxi
S
Chen
D055371:Acute Lung Injury / Q000139:chemically induced / Q000150:complications / Q000517:prevention & control*; D000818:Animals; D005260:Female; D007511:Ischemia / Q000150:complications* / Q000503:physiopathology; D019194:Ischemic Preconditioning / Q000379:methods*; D008070:Lipopolysaccharides; D035002:Lower Extremity / Q000098:blood supply*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
D008070:Lipopolysaccharides