Simple model of pulmonary hypertension secondary to left heart pressure overload induced by partial intravascular occlusion of the ascending aorta.

Pulmonary hypertension is a group of diseases characterized by elevated pulmonary artery pressure and pulmonary vascular resistance with significant morbidity and mortality. The most prevalent type is pulmonary hypertension secondary to left heart disease (PH-LHD). The available experimental models of PH-LHD use partial pulmonary clamping by technically nontrivial open-chest surgery with lengthy recovery.

Recovery from hypoxic pulmonary hypertension in rats.

To characterize the time frame of changes in pulmonary arterial pressure, right ventricular hypertrophy and morphology of small pulmonary arteries male Wistar rats were exposed to isobaric hypoxia (3 weeks, F1O2 0.1) and then let to recover on air for 1 or 5 weeks. Normoxic animals (group N) served as controls.

Prevention of mast cell degranulation by disodium cromoglycate attenuates the development of hypoxic pulmonary hypertension in rats exposed to chronic hypoxia.

Background: Chronic hypoxia induces lung vascular remodeling, which results in pulmonary hypertension. Vascular remodeling is associated with collagenolysis and activation of matrix metalloproteinases (MMPs). One of the possible sources of MMPs in hypoxic lung are mast cells.

Pulmonary vascular iNOS induction participates in the onset of chronic hypoxic pulmonary hypertension.

Pathogenesis of hypoxic pulmonary hypertension is initiated by oxidative injury to the pulmonary vascular wall. Because nitric oxide (NO) can contribute to oxidative stress and because the inducible isoform of NO synthase (iNOS) is often upregulated in association with tissue injury, we hypothesized that iNOS-derived NO participates in the pulmonary vascular wall injury at the onset of hypoxic pulmonary hypertension. An effective and selective dose of an iNOS inhibitor, L-N6-(1-iminoethyl)lysine (L-NIL), for chronic peroral treatment was first determined (8 mg/l in drinking water) by measuring exhaled NO concentration and systemic arterial pressure after LPS injection under ketamine+xylazine anesthesia.