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Updated: Jun 20, 2025
Implantation of an Isoproterenol Mini-Pump to Induce Heart Failure in Mice
Published on: October 3, 2019
Isoproterenol induced cardiac hypertrophy: A comparison of three doses and two delivery methods in C57BL/6J mice
Patricia Perez-Bonilla1, Brianna LaViolette1, Bidur Bhandary2
1Global Discovery, Investigative & Translational Sciences-Animal Models and Imaging, Pfizer Inc, Cambridge, Massachusetts, United States of America.
Insights
This study investigated isoproterenol (ISP) delivery methods for inducing heart failure in mice. Subcutaneous minipump infusion showed more pronounced heart weight increases than subcutaneous injection, suggesting delivery method impacts disease modeling.
Area of Science:
- Cardiology
- Pharmacology
- Animal Models
Background:
- Heart Failure (HF) and hypertrophic cardiomyopathy (HCM) prevalence are increasing globally.
- Heterogeneous etiology of HF and HCM hinders novel therapy development.
- Isoproterenol (ISP) is used to model HF and HCM in mice, but optimal protocols vary.
Purpose of the Study:
- To compare cardiac effects of ISP delivered via subcutaneous (SQ) and SQ-minipump (SMP) infusions.
- To determine optimal ISP dose and delivery for a reliable mouse model of cardiac disease.
- To assess if SQ and SMP ISP delivery induce comparable disease severity.
Main Methods:
- C57BL/6J mice received ISP (2, 4, 10mg/kg/day) via SQ or SMP for 2 weeks.
- Cardiac assessment included body/heart weight, ECG, echocardiography, and gene expression analysis.
- Evaluated hypertrophy and fibrosis markers.
Main Results:
- All ISP doses increased heart weight; SMP infusion showed more pronounced increases.
- Delivery methods induced contrasting heart rate, RR interval, and ECG amplitudes.
- SMP treatment increased heart wall thickness and LV Mass; SQ treatment increased hypertrophy/fibrosis gene markers.
Conclusions:
- Both SQ and SMP ISP delivery induce similar pathological heart phenotypes at 2 weeks.
- Drug delivery method significantly influences specific disease pathways and cardiac remodeling.
- Optimizing ISP delivery is crucial for reliable HF/HCM mouse models.
Abstract:
Heart Failure (HF) continues to be a complex public health issue with increasing world population prevalence. Although overall mortality has decreased for HF and hypertrophic cardiomyopathy (HCM), a precursor for HF, their prevalence continues to increase annually. Because the etiology of HF and HCM is heterogeneous, it has been difficult to identify novel therapies to combat these diseases. Isoproterenol (ISP), a non-selective β-adrenoreceptor agonist, is commonly used to induce cardiotoxicity and cause acute and chronic HCM and HF in mice. However, the variability in dose and duration of ISP treatment used in studies has made it difficult to determine the optimal combination of ISP dose and delivery method to develop a reliable ISP-induced mouse model for disease. Here we examined cardiac effects induced by ISP via subcutaneous (SQ) and SQ-minipump (SMP) infusions across 3 doses (2, 4, and 10mg/kg/day) over 2 weeks to determine whether SQ and SMP ISP delivery induced comparable disease severity in C57BL/6J mice. To assess disease, we measured body and heart weight, surface electrocardiogram (ECG), and echocardiography recordings. We found all 3 ISP doses comparably increase heart weight, but these increases are more pronounced when ISP was administered via SMP. We also found that the combination of ISP treatment and delivery method induces contrasting heart rate, RR interval, and R and S amplitudes that may place SMP treated mice at higher risk for sustained disease burden. Mice treated via SMP also had increased heart wall thickness and LV Mass, but mice treated via SQ showed greater increase in gene markers for hypertrophy and fibrosis. Overall, these data suggest that at 2 weeks, mice treated with 2, 4, or 10mg/kg/day ISP via SQ and SMP routes cause similar pathological heart phenotypes but highlight the importance of drug delivery method to induce differing disease pathways.
