Related Experiment Video
Updated: Aug 16, 2026
Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors
Published on: June 7, 2016
Imaging the renin-angiotensin- aldosterone system in the heart
Jamshid Shirani1, Maria L Loredo, William C Eckelman
1Geisinger Medical Center, Division of Cardiology, 100 North Academy Avenue, Danville, PA 17822, USA. jshirani1@geisinger.edu
Abstract:
The influence of the renin-angiotensin system (RAS) is recognized in cardiac and vascular injury. An extrinsic RAS has been known for decades, and an equally important intrinsic RAS has been discovered recently. The latter leads to pathologic tissue alterations in the absence of systemic stimuli and may be the main source of local tissue effects of RAS. A new radiotracer fluorobenzoyl-lisinopril was synthesized by radiolabeling benzoic acid active ester with 18F and reacting that with the epsilon-amino group of lisinopril. The presence of angiotensin-converting enzyme (ACE) activity and angiotensin II receptors was examined in relation to myocardial fibrosis. This tissue-specific radioligand represents the first study of ACE in the human heart. This article presents preliminary data on imaging the RAS in the human cardiac tissue and discusses the potential for clinical application of these imaging techniques to human patients.
Insights
Researchers developed a novel radiotracer to image the cardiac renin-angiotensin system (RAS) and its role in myocardial fibrosis. This imaging technique offers potential for diagnosing heart conditions in patients.
Area of Science:
- Cardiovascular Research
- Medical Imaging
- Biochemistry
Background:
- The renin-angiotensin system (RAS) significantly impacts cardiac and vascular health.
- Both extrinsic and intrinsic RAS pathways are implicated in tissue injury.
- Intrinsic RAS may drive local pathological changes independently of systemic factors.
Purpose of the Study:
- To synthesize a novel radiotracer, fluorobenzoyl-lisinopril, for imaging the cardiac RAS.
- To investigate the presence of angiotensin-converting enzyme (ACE) activity and angiotensin II receptors in human cardiac tissue.
- To explore the relationship between RAS components and myocardial fibrosis using this new imaging agent.
Main Methods:
- Synthesis of the 18F-labeled radiotracer fluorobenzoyl-lisinopril.
- Application of the radiotracer to examine ACE activity and angiotensin II receptors in human cardiac tissue.
- Correlation of imaging findings with myocardial fibrosis.
Main Results:
- Successful synthesis of the novel radiotracer fluorobenzoyl-lisinopril.
- Preliminary data demonstrating the feasibility of imaging the RAS in human cardiac tissue.
- This study represents the first investigation of ACE in the human heart using a tissue-specific radioligand.
Conclusions:
- The developed radiotracer enables visualization of the cardiac RAS.
- This imaging approach holds promise for assessing RAS-related myocardial fibrosis.
- Potential clinical applications for diagnosing and managing cardiovascular diseases are discussed.
Related Concept Videos
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
01:29Heart Failure II: Pathophysiology
01:19Imaging Studies VII: Vascular Imaging
01:20Imaging Studies for Cardiovascular System III: X-Ray
Definition and Purpose
An X-ray, or radiograph, is a non-invasive method that uses ionizing radiation to take images of internal structures. It is mainly used in cardiac imaging to examine the heart, lungs, and major blood vessels, aiming to identify abnormalities in the heart's size, shape, and position, such as heart failure, congenital defects, and vascular...