Arterial morphology responds differently to Captopril then N-acetylcysteine in a monocrotaline rat model of pulmonary hypertension
2010
Pulmonary hypertension (PH) is an incurable condition inevitably resulting in death because of increased right
heart workload and eventual failure. PH causes pulmonary vascular remodeling, including muscularization of
the arteries, and a reduction in the typically large vascular compliance of the pulmonary circulation. We used a
rat model of monocrotaline (MCT) induced PH to evaluated and compared Captopril (an angiotensin
converting enzyme inhibitor with antioxidant capacity) and N-acetylcysteine (NAC, a mucolytic with a large
antioxidant capacity) as possible treatments. Twenty-eight days after MCT injection, the rats were sacrificed
and heart, blood, and lungs were studied to measure indices such as right ventricular hypertrophy (RVH),
hematocrit, pulmonary vascular resistance (PVR), vessel morphology and biomechanics. We implemented
microfocal X-ray computed tomography to image the pulmonary arterial tree at intravascular pressures of 30,
21, 12, and 6 mmHg and then used automated vessel detection and measurement algorithms to perform
morphological analysis and estimate the distensibility of the arterial tree. The vessel detection and
measurement algorithms quickly and effectively mapped and measured the vascular trees at each intravascular
pressure. Monocrotaline treatment, and the ensuing PH, resulted in a significantly decreased arterial
distensibility, increased PVR, and tended to decrease the length of the main pulmonary trunk. In rats with PH
induced by monocrotaline, Captopril treatment significantly increased arterial distensibility and decrease PVR.
NAC treatment did not result in an improvement, it did not significantly increase distensibility and resulted in
further increase in PVR. Interestingly, NAC tended to increase peripheral vascular density. The results suggest
that arterial distensibility may be more important than distal collateral pathways in maintaining PVR at
normally low values.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
0
References
1
Citations
NaN
KQI