MMP8 and pulmonary hypertension: MMP-8 has also been implicated in the pathogenesis of pulmonary hypertension (PH), with studies demonstrating elevated levels in the pulmonary arteries and peripheral circulation of patients with PH, increased expression in rodent models of PH, and an association between elevated MMP 8 and right ventricular end diastolic volume in patients with PH [24, 25].