PMID- 8454952
OWN - NLM
STAT- MEDLINE
DCOM- 19930422
LR  - 20190516
IS  - 0741-5400 (Print)
IS  - 0741-5400 (Linking)
VI  - 53
IP  - 3
DP  - 1993 Mar
TI  - Bidirectional modulation of TNF-alpha production by alveolar macrophages in 
      asbestos-induced pulmonary fibrosis.
PG  - 279-86
AB  - Bronchoalveolar lavage (BAL) cells were isolated from rats 1, 3, and 6 weeks 
      after a single intratracheal instillation of saline, UICC chrysotile asbestos (5 
      mg), or silica (5 mg). In asbestos-exposed rats, the pulmonary response was 
      characterized by a significant increase in the number of alveolar macrophages 
      (AMs) and the appearance of fibrotic lesions within 1 week. By contrast, mixed 
      macrophage and neutrophil accumulations were observed in the silica group without 
      evidence of fibrosis. Tumor necrosis factor-alpha (TNF-alpha) production by 
      lipopolysaccharide (LPS)-stimulated BAL cells from asbestos-treated rats was 
      significantly lower than controls 1 and 3 weeks after exposure. However, by 6 
      weeks higher levels of TNF-alpha production were noticeable in this group. 
      Decreases in LPS-induced TNF-alpha production were also observed with BAL cells 
      from silica-treated animals at all time points studied. Lower levels of TNF-alpha 
      were not related to decreased BAL cell viability or the presence of a significant 
      proportion of neutrophils in the silica group. Furthermore, biphasic changes in 
      TNF-alpha production seen in the asbestos group were correlated with concomitant 
      decreases (3 weeks) and increases (6 weeks) in levels of TNF-alpha mRNA in AMs. 
      These data indicate that lower levels of TNF-alpha resulted from inhibition at 
      the gene expression level and provide evidence for bidirectional modulation of 
      TNF-alpha production by AMs during inflammatory reactions.
FAU - Ouellet, S
AU  - Ouellet S
AD  - Department of Pharmacology, Faculty of Medicine, University of Ottawa, Ottawa, 
      Canada.
FAU - Yang, H
AU  - Yang H
FAU - Aubin, R A
AU  - Aubin RA
FAU - Hawley, R G
AU  - Hawley RG
FAU - Wenckebach, G F
AU  - Wenckebach GF
FAU - Lemaire, I
AU  - Lemaire I
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Leukoc Biol
JT  - Journal of leukocyte biology
JID - 8405628
RN  - 0 (Tumor Necrosis Factor-alpha)
RN  - 1332-21-4 (Asbestos)
SB  - IM
GS  - TNF-&agr;
MH  - Animals
MH  - Asbestos/*adverse effects
MH  - Bronchoalveolar Lavage Fluid/cytology
MH  - Cell Survival
MH  - Down-Regulation
MH  - Gene Expression Regulation
MH  - Macrophages, Alveolar/*metabolism
MH  - Male
MH  - Neutrophils/physiology
MH  - Pulmonary Fibrosis/*etiology/*metabolism
MH  - Rats
MH  - Rats, Wistar
MH  - Tumor Necrosis Factor-alpha/genetics/*metabolism
MH  - Up-Regulation
EDAT- 1993/03/01 00:00
MHDA- 1993/03/01 00:01
CRDT- 1993/03/01 00:00
PHST- 1993/03/01 00:00 [pubmed]
PHST- 1993/03/01 00:01 [medline]
PHST- 1993/03/01 00:00 [entrez]
AID - 10.1002/jlb.53.3.279 [doi]
PST - ppublish
SO  - J Leukoc Biol. 1993 Mar;53(3):279-86. doi: 10.1002/jlb.53.3.279.