The influence of oestrogen-deficiency and ACE inhibition on the progression of myocardial hypertrophy in spontaneously hypertensive rats.

摘要

BACKGROUND: ACE inhibitors are widely used to antagonize the biological activity of angiotensin II in hypertensive heart disease. Oestrogen reduces angiotensin type 1 receptor expression, and thereby modifies angiotensin signalling. AIM: To investigate the interaction of oestrogen status and ACE inhibition on the development of left ventricular hypertrophy and expression of transforming growth factor (TGF)-beta(1) in female spontaneously hypertensive rats (SHR). METHODS AND RESULTS: Intact female SHR, ovariectomised SHR, and ovariectomised SHR with 17beta-oestradiol (E2) replacement therapy were either treated with placebo or the ACE inhibitor moexiprilat. Blood pressure, left ventricular hypertrophy, and expression of TGF-beta(1) and TGF-beta(1)-regulated genes were investigated. ACE inhibition reduced blood pressure in all groups. When normalised to blood pressure, a significant reduction in hypertrophy was found in ovariectomised animals receiving E2. Expression of TGF-beta(1) was increased in all three groups treated with the ACE inhibitor, with top levels in ovariectomised animals. Moreover, expression of ornithine decarboxylase (ODC), an adrenoceptor dependent gene, downstream of TGF-beta(1), was up-regulated upon ACE inhibition, except in animals which were ovariectomised and oestrogen supplemented. Parathyroid hormone-related peptide, a growth factor negatively regulated by TGF-beta(1), was down-regulated in all animals receiving the ACE inhibitor. CONCLUSION: ACE inhibition modulated TGF-beta(1) and TGF-beta(1) dependent genes. Oestrogen deficiency alone did not influence the progression of cardiac hypertrophy in this model of female SHR.