[Effects of metalloproteinases on pulmonary fibrosis by bleomycin in rats].
OBJECTIVE
Matrix metalloproteinases (MMPs) are the mediators for dynamic equilibrium of extracellular matrix. The purpose was to investigate the effects of metalloproteinases on the development of pulmonary fibrosis.


METHODS
The expression and activity of metalloproteinases of alveolar macrophage, and fibroblasts were evaluated on rats with pulmonary fibrosis induced by bleomycin.


RESULTS
The activity of collagenase was low in the macrophage and fibroblast in control group, 20.4 x 10(-7) U/cell and 30.6 x 10(-7) U/cell respectively. There was an increase in the first and fourth week groups of bleomycin rats. The highest level of activity of alveolar macrophages was 258.0 x 10(-7) U/cell in first week group. A peak of enzymatic activity was found in 4th week group (289.0 x 10(-7) U/cell). The mRNA of MMP-1, MMP-2 were expressed at lower levels in the normal lung tissue and there was an increase in first week, and fourth week group of bleomycin rats with a peak in one week group.


CONCLUSIONS
The regulation of metalloproteinases might play an important role in the development of pathological processes in pulmonary fibrosis.
Liu
X
X
Respiratory Department of the First Teaching Hospital of Beijing Medical University, Beijing 100034.
Xu
S
S
He
B
B
Tan
W
W
D000818:Animals; D001761:Bleomycin / Q000633:toxicity*; D017364:Collagenases / Q000502:physiology; D008168:Lung / Q000201:enzymology*; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000502:physiology; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000502:physiology; D008666:Metalloendopeptidases / Q000502:physiology*; D011658:Pulmonary Fibrosis / Q000139:chemically induced* / Q000201:enzymology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar
D012333:RNA, Messenger; D001761:Bleomycin; D017364:Collagenases; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020781:Matrix Metalloproteinase 1