Related Experiment Video
Updated: Jul 6, 2026
07:31
A Model of Cardiac Remodeling Through Constriction of the Abdominal Aorta in Rats
Published on: December 2, 2016
Effect of low thyroid function on cardiac structure and function in spontaneously hypertensive heart failure rats
Bassel Kisso1, Ankit Patel, Rebecca Redetzke
1Cardiovascular Research Institute, Sanford Research/University of South Dakota, 1100 East 21st Street, Sioux Falls, SD 57105, USA.
Journal of Cardiac Failure
|March 8, 2008
Summary
Induced hypothyroidism in hypertensive rats caused heart dysfunction but not arteriolar loss. These findings suggest hypothyroidism worsens cardiac changes in hypertension without further damaging microvasculature.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
Background:
- Hypothyroidism negatively impacts the cardiovascular system, including microvasculature.
- Pathophysiological effects of hypothyroidism in hypertensive individuals remain unclear.
Purpose of the Study:
- To investigate the cardiovascular and microvascular consequences of induced hypothyroidism in spontaneously hypertensive heart failure (SHHF) rats.
Main Methods:
- Female SHHF rats were treated with propylthiouracil (PTU) to induce hypothyroidism for 6 months.
- Control groups included untreated SHHF rats and normotensive Wistar Furth (WF) rats.
- Measurements included heart weight, echocardiography, hemodynamics, and arteriolar morphometry.
Main Results:
- PTU-treated SHHF rats exhibited increased left ventricular dimensions and decreased ejection fraction, heart rate, systolic blood pressure, and cardiac contractility.
- Surprisingly, no differences in arteriolar density were observed among the groups.
- Induced hypothyroidism led to systolic dysfunction and chamber dilation in SHHF rats.
Conclusions:
- Hypothyroidism induced detrimental cardiac changes in SHHF rats, including systolic dysfunction and chamber dilation.
- Unlike in normotensive rats, PTU treatment did not cause arteriolar loss in SHHF rats.
- The cardiovascular effects of hypothyroidism in hypertensive rats were comparable to those in normotensive rats.
More Related Videos
Related Concept Videos
01:29Heart Failure II: Pathophysiology
Systolic Heart Failure and Compensatory MechanismsSystolic heart failure (also termed HFrEF, Heart Failure with Reduced Ejection Fraction) is the most prevalent type of heart filure. It results in a decreased volume of blood being pumped from the ventricle. The aortic arch and carotid sinuses have baroreceptors that detect reduced blood pressure, triggering the sympathetic nervous system (SNS) to release epinephrine and norepinephrine. Initially, this response aims to boost heart rate and...
01:27Heart Failure I: Introduction
Heart failure refers to a clinical syndrome caused by structural or functional cardiac disorders that prevent the heart from pumping an adequate amount of blood to meet the body's metabolic needs. This condition often arises from myocardial infarction or ischemia, leading to decreased cardiac output, reduced tissue perfusion, impaired gas exchange, fluid volume imbalance, and decreased functional ability.Heart failure can result from disruptions in the mechanisms that regulate cardiac output...
01:17Pathophysiology of Heart Failure
Heart failure (HF) is a progressive syndrome involving ventricles that leads to inadequate cardiac output. It can be classified based on location and output or ejection fraction. Ejection fraction (EF) is an essential measurement in the diagnosis and surveillance of HF. Reduced EF corresponds to systolic heart failure (HFrEF). However, HF with preserved ejection fraction (HFpEF) is becoming increasingly prevalent. Also known as diastolic HF, this form of HF is related to aging. The...
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral...