The influence of gender on cardiac fibrosis induced by sympathetic stimulation
Related Experiment Video
Updated: Jun 28, 2026
Scanning Electron Microscopy of Macerated Tissue to Visualize the Extracellular Matrix
Published on: June 14, 2016
Yasutomo Hori1, Masami Uechi, Takashi Ebisawa
1Department of Veterinary Medicine, School of Veterinary Medicine and Animal Science, Kitasato University, 23-35-1 Higashi, Towada, Aomori 034-8628, Japan.
Abstract:
We examined the influence of sex steroids on cardiac effects of sympathetic agents in mice. The mice were divided into four groups: males, neutered males (N-males), females, and neutered females (N-females). Dobutamine (DOB; 2.5, 5.0, 10 microg/kg/min) or isoproterenol (ISO; 0.01, 0.02, 0.04 microg/kg/min) were given intravenously to compare the fractional shortening (FS). These mice received isoproterenol twice daily at a dose of 7.5 microg/g/day for 3 weeks. The rate of cardiac fibrosis was evaluated pathologically with Azan stain after 3 weeks of ISO. DOB and ISO significantly increased the FS in the male group, compared with other groups. There was no significant difference in FS between the female and N-female groups. Cardiac fibrosis significantly increased in the male group, compared with the N-male group. The female and N-female groups had increased cardiac fibrosis, compared with the male and N-male groups. These findings suggest that testosterone is one of the factors of modulation of the response to the sympathetic nervous system. Further study is needed to clarify the relationships between female sex steroids and cardiac fibrosis.
Insights
Testosterone modulates cardiac responses to sympathetic agents like dobutamine and isoproterenol in mice. Sex steroids significantly impact cardiac fibrosis development, with testosterone playing a key role.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Pharmacology
Background:
- Sex steroids are known to influence various physiological processes.
- The role of sex steroids in modulating the cardiovascular response to sympathetic stimulation requires further elucidation.
- Understanding these interactions is crucial for cardiovascular health.
Purpose of the Study:
- To investigate the influence of sex steroids on the cardiac effects of sympathetic agents in mice.
- To compare the cardiac response and fibrosis development between male, neutered male, female, and neutered female mice.
- To determine the specific role of testosterone in modulating sympathetic nervous system effects on the heart.
Main Methods:
- Mice were divided into four groups: males, neutered males (N-males), females, and neutered females (N-females).
- Intravenous administration of dobutamine (DOB) and isoproterenol (ISO) to assess fractional shortening (FS).
- Pathological evaluation of cardiac fibrosis using Azan stain after 3 weeks of isoproterenol administration.
Main Results:
- Dobutamine and isoproterenol significantly increased fractional shortening in male mice compared to other groups.
- No significant difference in fractional shortening was observed between female and neutered female groups.
- Cardiac fibrosis was significantly higher in male mice compared to neutered males, and higher in both female groups compared to males.
Conclusions:
- Testosterone appears to be a key factor in modulating the cardiovascular response to sympathetic nervous system stimulation.
- Female sex steroids are associated with increased cardiac fibrosis, warranting further investigation.
- These findings highlight the differential impact of sex steroids on cardiac function and pathology.
Related Concept Videos
01:29Heart Failure II: Pathophysiology
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
01:17Pathophysiology of Heart Failure
01:21Myocarditis I: Introduction
01:23Rheumatic Heart Disease I: Introduction
01:26Imbalances in Cardiac Output
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send blood...