AJP - Lung Cellular and Molecular Physiology, Vol 266, Issue 6 722-L727, Copyright © 1994 by American Physiological Society
Immunochemical detection of inducible NO synthase in human lung
W. R. Tracey, C. Xue, V. Klinghofer, J. Barlow, J. S. Pollock, U. Forstermann and R. A. Johns
Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, Illinois 60064-3500.
Type II (inducible) nitric oxide synthase (NOS) may play an important role
in pulmonary pathophysiology, yet it remains controversial whether human
tissues are capable of expressing this protein. Therefore, a polyclonal
antibody (8196) was raised against type II NOS from induced RAW 264.7
macrophages and used to investigate the expression of this enzyme in human
lung tissue. Anti-type II NOS antibody did not cross-react with either
neuronal (type I) or endothelial (type III) constitutive NOS, whereas a
130-kDa protein was detected in cytosol from induced macrophages or liver
removed from lipopolysaccharide (25 mg/kg)-treated rats. Cells or tissues
that lacked NOS activity did not express immunoreactive proteins.
Similarly, in grossly normal human lung tissue, no immunoreactivity was
detected with the anti-type II NOS antibody. In contrast, strong
immunoreactivity was detected in alveolar macrophages present in lung
tissue from a patient with bronchiectasis and acute bronchopneumonia. These
data demonstrate that human alveolar macrophages are able to express type
II NOS and support a role for this enzyme in pulmonary inflammatory
pathophysiology.
