Load versus humoral activation in the genesis of early hypertensive heart disease
Summary
This summary is machine-generated.Hypertension causes heart changes like hypertrophy and fibrosis without increasing Ang II or ET. These structural and functional changes in early hypertensive heart disease are primarily driven by increased blood pressure (load).
Area Of Science
- Cardiovascular Physiology
- Renal Hypertension
- Cardiac Pathophysiology
Background
- The relative contributions of blood pressure (load), angiotensin II (Ang II), and endothelin-1 (ET) to hypertensive heart disease are debated.
- This study investigated whether cardiac structural and functional alterations in hypertension depend on Ang II or ET activation.
Purpose Of The Study
- To determine the role of Ang II and ET in the development of hypertensive heart disease.
- To elucidate the primary drivers of cardiac changes in early-stage hypertension.
Main Methods
- Adult dogs underwent bilateral renal wrapping to induce hypertension (HTN) or sham surgery.
- Blood pressure, plasma hormones (Ang II, ET, catecholamines), and cardiac function (Ees, tau) were monitored over 12 weeks.
- Left ventricular (LV) and kidney tissue were analyzed for Ang II and ET levels.
Main Results
- Renal wrap dogs showed significantly elevated mean arterial pressure compared to controls.
- Left ventricular mass index and fibrosis increased in hypertensive dogs.
- Diastolic dysfunction (increased tau) was observed, while systolic function (Ees) remained preserved.
- Plasma levels of Ang II, ET, catecholamines, and renin activity did not change significantly.
- Ang II and ET levels in the LV and kidney were comparable between hypertensive and control groups.
Conclusions
- Systemic hypertension induces left ventricular hypertrophy, myocardial fibrosis, and isolated diastolic dysfunction.
- These cardiac changes occur independently of local or systemic Ang II or ET activation.
- Increased vascular load, rather than Ang II or ET, appears to be the main stimulus for early hypertensive heart disease.
View abstract on PubMed