Steroid responsiveness of fibroblasts of paraquat injured lungs.
We evaluated the effect of dexamethasone on the synthesis of fibronectin by rat lung fibroblasts. A dose dependent inhibition was observed in fibroblasts isolated from normal lungs and in fibroblasts isolated early (4 days) and late (14 days) after the administration of endobronchial paraquat, and was more pronounced in fibroblasts exposed to dexamethasone for longer durations of time. Fibroblasts isolated early were more responsive to the inhibitory effects of dexamethasone on fibronectin synthesis. In addition, the distribution of fibronectin between the cellular and the extracellular compartments in these cells was altered. We conclude that fibroblasts of repairing lungs undergo changes in their responsiveness to corticosteroids during the repair process and are more susceptible to such therapeutic agents during the acute phase of injury.
Dubaybo
B A
BA
Pulmonary Section, VAMC, Allen Park, MI.
Marwah
G S
GS
Rubeiz
G J
GJ
D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D005353:Fibronectins / Q000096:biosynthesis; D066298:In Vitro Techniques; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D055370:Lung Injury; D008297:Male; D010269:Paraquat; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344
D005353:Fibronectins; D003907:Dexamethasone; D010269:Paraquat