Context: Oestrogen deficiency is linked with pulmonary fibrosis. Additionally, it may lead to over-activation
of the renin-angiotensin system (RAS), which worsens lung fibrosis.
Objective: The present study aims to investigate the role of RAS on lung fibrosis associated with oestrogen
deficiency in ovariectomised rats.
Materials and methods: Serum 17b-oestradiol (E2), arterial blood gases, plasma angiotensin II levels,
lung tissue hydroxyproline content, and transforming growth factor beta 1 (TGF-b1) concentration, the
mRNA expression of angiotensin type 1 receptor (AT1R), and angiotensin-converting enzyme (ACE1)
were evaluated. Moreover, lung tissues were examined by histopathology and immunohistochemistry.
Results: Hydroxyproline content, TGF-b1 concentration, plasma angiotensin II, the relative mRNA
expression of ACE1, and AT1R is found to increase in ovariectomised rats. The mentioned changes can
be largely rescued by administration of RAS blockers.
Conclusion: Oestrogen deficiency activates RAS, which consequently increases the expression of
pro-fibrotic factors and stimulates the fibrotic cascade causing lung fibrosis. |
