Related Experiment Video
Updated: May 21, 2025
Murine Orchiectomy and Ovariectomy to Reduce Sex Hormone Production
Published on: November 17, 2023
Testosterone Deprivation Impairs Cardiac Systolic Function in Orchiectomized Wistar Rats
Gabriela Almeida Motta1, Graziele Halmenschlager1,2, Rachel Pinto Dornelles Dutra1
1Biociências, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Brazil.
Insights
Testosterone deficiency in rats impaired cardiac systolic function, indicated by reduced fractional shortening and altered mitral valve closure time. This study highlights testosterone
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Male Reproductive System
Background:
- Low testosterone levels are associated with cardiac disease and cardiovascular mortality.
- The precise impact of testosterone deficiency on cardiac systolic function and morphology remains unclear.
Purpose of the Study:
- To investigate the effects of testosterone deprivation on cardiac systolic function and morphology in male Wistar rats.
Main Methods:
- Male Wistar rats were divided into sham operation and orchiectomized groups.
- Echocardiographic parameters were assessed to evaluate left ventricle (LV) systolic function and morphology.
- Serum testosterone levels were analyzed before and after surgery.
Main Results:
- Orchiectomized rats exhibited reduced LV fractional shortening, increased myocardial performance index (MPI), prolonged mitral valve closure time, and decreased heart rate compared to controls.
- No significant difference in ejection fraction was observed between groups.
- Heart weight was significantly lower in the orchiectomized group.
Conclusions:
- Testosterone deprivation negatively impacts cardiac systolic function, affecting contraction and relaxation parameters.
- Testosterone deficiency alters heart rate and heart weight.
- This study is the first to demonstrate that reduced testosterone levels can alter specific cardiac parameters like mitral valve closing time and MPI.
Abstract:
Several studies have linked low levels of testosterone with increased symptoms of cardiac disease and cardiovascular mortality; however, the effects of testosterone deficiency on cardiac systolic function and morphology are still not completely elucidated. The present study aims to evaluate the influence of testosterone deprivation on cardiac systolic function and morphology. Male Wistar rats were divided into two groups: Sham operation group (Sham): animals underwent sham operation and Orchiectomized group (Orchiec): animals underwent bilateral orchiectomy. The experimental protocol lasted 60 days after the surgery. All animals were weighted and blood samples collected to serum testosterone analysis, determined by chemiluminescence, on first (before orchiectomy) and on 60th days. One day before euthanasia (on the 59th day) echocardiographic parameters were assessed to evaluate left ventricle (LV) systolic function and morphology. Statistical significant difference was set at≤0.05. Orchiec rats presented reduced LV fractional shortening (p=0.032), increased myocardial performance index (MPI) (p=0.043), prolonged mitral valve closure time (p=0.013) and decreased heart rate (p=0.049) when compared to Sham. No statistically significant difference was found in the ejection fraction (p=0.666) between groups. Besides that, heart weight was lower in Orchiec group (p=0.035) when compared to Sham group. Testosterone deprivation reduced cardiac systolic function, changing contraction and relaxation parameters. Testosterone deficiency also changed heart rate and heart weight. The present study demonstrated for the first time that castrated levels of testosterone could alter parameters such as mitral valve closing time and MPI.
