MMP9 and pulmonary arterial hypertension: Other anti-inflammatory therapies, such as treatment with resveratrol, were similarly able to prevent PA remodeling and stiffening in chronic hypoxic rats (215), while inhibitors of the renin–angiotensin system such as captopril or losartan reduced the production of ECM components including interstitial collagen and the expression of MMP-2 and MMP-9 in PAH, thereby attenuating PA stiffening (215).