چکیده (انگلیسی):

Background: Rapamycin has been reported to inhibit mesenchymal cell proliferation in a murine model of
pulmonary fibrosis. In the present study, we examined the effects of rapamycin on vascular remodeling including
intraluminal myofibroblast proliferation in a murine model of allergic vasculitis with eosinophil infiltration.
Methods: C57BL6 mice were sensitized with ovalbumin (OVA) and alum. The positive controls were exposed
to aerosolized OVA daily for 7 days. The other group of mice was administered with rapamycin (1 mg
kg) intraperitoneally, in parallel with daily exposure to aerosolized OVA for 7 days. On the 3rd and 7th day, bronchoalveolar
lavage (BAL) was performed and the lungs were excised for pathological analysis. Cell differentials
were determined and concentrations of IL-4, IL-5, IL-13 and TGF-β in the BAL fluid (BALF) were measured.
Semi-quantitative analysis of pathological changes in the pulmonary arteries was evaluated according to the
severity of vasculitis.
Results: The number of eosinophils in BALF was reduced significantly in the mice treated with rapamycin
compared to the positive control. There was a significant decrease in the TGF-β concentration of the BALF in
the rapamycin-treated group compared to that of the positive control. The pathological scores were reduced
significantly in the rapamycin-treated group compared to the positive control group. Intraluminal myofibroblasts
in pulmonary arteries were reduced dramatically in the rapamycin-treated group compared to the positive control
group.
Conclusions: Rapamycin suppressed pulmonary vascular remodeling in a murine model of allergic vasculitis
with eosinophil infiltration through reducing eosinophil infiltration and TGF-β production in the lung and inhibition
against biological action of TGF-β.