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Updated: Apr 6, 2026
Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice
Published on: September 17, 2015
Comparative effects of urocortins and stresscopin on cardiac myocyte contractility
Catherine A Makarewich1, Constantine D Troupes1, Sarah M Schumacher2
1Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Physiology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
Rationale:
There is a current need for the development of new therapies for patients with heart failure.
Objective:
We test the effects of members of the corticotropin-releasing factor (CRF) family of peptides on myocyte contractility to validate them as potential heart failure therapeutics.
Methods And Results:
Adult feline left ventricular myocytes (AFMs) were isolated and contractility was assessed in the presence and absence of CRF peptides Urocortin 2 (UCN2), Urocortin 3 (UCN3), Stresscopin (SCP), and the β-adrenergic agonist isoproterenol (Iso). An increase in fractional shortening and peak Ca(2+) transient amplitude was seen in the presence of all CRF peptides. A decrease in Ca(2+) decay rate (Tau) was also observed at all concentrations tested. cAMP generation was measured by ELISA in isolated AFMs in response to the CRF peptides and Iso and significant production was seen at all concentrations and time points tested.
Conclusions:
The CRF family of peptides effectively increases cardiac contractility and should be evaluated as potential novel therapeutics for heart failure patients.
Insights
Corticotropin-releasing factor (CRF) peptides like Urocortin 2 and 3 enhance cardiac contractility. These findings suggest CRF peptides are promising new heart failure therapeutics.
Area of Science:
- Cardiovascular Physiology
- Pharmacology
Background:
- Heart failure necessitates novel therapeutic strategies.
- Current treatments for heart failure have limitations.
Purpose of the Study:
- To investigate the potential of corticotropin-releasing factor (CRF) peptides as heart failure therapeutics.
- To assess the effects of CRF family peptides on cardiac myocyte contractility.
Main Methods:
- Isolated adult feline left ventricular myocytes (AFMs) were used.
- Myocyte contractility, Ca(2+) transients, and cAMP generation were measured.
- CRF peptides (UCN2, UCN3, SCP) and isoproterenol were tested.
Main Results:
- All tested CRF peptides increased fractional shortening and peak Ca(2+) transient amplitude.
- CRF peptides decreased Ca(2+) decay rate (Tau).
- CRF peptides stimulated significant cAMP generation in AFMs.
Conclusions:
- CRF family peptides demonstrate efficacy in increasing cardiac contractility.
- These peptides represent potential novel therapeutic agents for heart failure.
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