Modulation of lipopolysaccharide-induced acute lung inflammation: Role of insulin.
The present study was undertaken to investigate the influence of insulin on lipopolysaccharide (LPS)-induced acute lung injury. Diabetic male Wistar rats (alloxan, 42 mg/kg, i.v., 30 days) and controls were instilled with saline containing LPS (750 microg/0.4 mL) or saline alone. The following analyses were performed 6 h there after: (a) total and differential cell counts in bronchoalveolar lavage (BAL) fluid, (b) quantification of tumor necrosis factor alpha, interleukin (IL) 1beta, IL-10, and cytokine-induced neutrophil chemoattractant 1 in the BAL (enzyme-linked immunosorbent assay), (c)immunohistochemistry for intercellular adhesion molecule 1 and E-selectin on lung vessels, and (d) quantification of metalloproteinases (MMP) 2 and 9 in the BAL (zymography). Relative to controls, diabetic rats exhibited a reduction in the number of neutrophils (80%) and reduced concentrations of tumor necrosis factor alpha (56%), IL-1beta (66%), and IL-10 (35%) after LPS instillation. Cytokine-induced neutrophil chemoattractant 1 levels did not differ between groups. Increased levels of MMP-2 (90%) and MMP-9 (500%) were observed in diabetic rats compared with controls. Treatment of diabetic rats with neutral protamine Hagedorn insulin (4 IU, s.c.), 2 h before LPS instillation, completely restored the number of neutrophils and concentrations of cytokines in the BAL fluid. Despite no significant differences between diabetic and control groups, there was a remarkable increase in intercellular adhesion molecule 1 and E-selectin expression on lung vessels after insulin treatment. Levels of MMP-2 and MMP-9 did not change after treatment with insulin. Levels of corticosterone were equivalent among groups. Data presented suggest that insulin modulates the production/release of cytokines and the expression of adhesion molecules controlling, therefore, neutrophil migration during the course of LPS-induced acute lung inflammation.
de Oliveira Martins
Joilson
J
Research Division, Heart Institute (InCor), LIM-11, University of São Paulo Medical School, São Paulo, SP, Brazil.
Meyer-Pflug
Adriano Ribeiro
AR
Alba-Loureiro
Tatiana Carolina
TC
Melbostad
Heidi
H
Costa da Cruz
José Walber Miranda
JW
Coimbra
Raul
R
Curi
Rui
R
Sannomiya
Paulina
P
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D018925:Chemokines / Q000097:blood; D003345:Corticosterone / Q000097:blood; D016207:Cytokines / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D019040:E-Selectin / Q000378:metabolism; D007249:Inflammation / Q000139:chemically induced / Q000517:prevention & control*; D007328:Insulin / Q000097:blood*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015430:Weight Gain
D001786:Blood Glucose; D018925:Chemokines; D016207:Cytokines; D019040:E-Selectin; D007328:Insulin; D008070:Lipopolysaccharides; D018799:Intercellular Adhesion Molecule-1; D003345:Corticosterone