[Inhibitory effect of rat alveolar type II cells on production of superoxide by neutrophils].
Neutrophils induce lung injury by releasing superoxides (O2-) and elastases. Alveoli contain anti-neutrophil agents such as surfactant. We studied the effects of alveolar type II cells on neutrophil functions. Neutrophils were isolated from human venous blood and their O2- production was measured by the cytochrome C reduction method. Type II cells and fibroblasts were isolated from rat lungs. Neutrophil O2-production was inhibited in the presence of type II cells. This effect was specific to type II cells: fibroblasts caused no inhibition. The inhibition did not require cell-to-cell contact, and it was abolished by the nitric oxide synthase inhibitor L-NAME. These results show that type II cells can inhibit neutrophil O2-production, and suggest that anti-neutrophil activity in alveoli may involve both surfactant and type II cells.
Suwabe
A
A
Department of Laboratory Medicine, Yamagata University School of Medicine.
Itasaka
M
M
Suzuki
H
H
Ito
M
M
Takahashi
K
K
D000818:Animals; D006801:Humans; D008297:Male; D009504:Neutrophils / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000166:cytology / Q000502:physiology*; D011663:Pulmonary Surfactants / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013481:Superoxides / Q000378:metabolism*
D011663:Pulmonary Surfactants; D013481:Superoxides