Isoproterenol Induces Cardiac Injury and Senescence in Sprague-Dawley Rats: A Cost-Effective Pharmacological Model

Background/Objectives: Cardiovascular disease increases with ageing and remains the leading cause of death worldwide. Cellular senescence contributes to cardiac dysfunction in the older population by secreting the senescence-associated secretory phenotype (SASP). Cardiac injury models induced by surgery have been shown to induce senescence in young adult rodents. However, surgical models are complex and associated with high mortality. Methods: We established a rat model of injury and senescence using isoproterenol (ISO). Male SD rats received ISO (100 mg/kg) for five days, then hearts were collected on days 10 and 28 after the first ISO dose. Results: ISO administration caused cardiac injury, manifested by inflammatory infiltration, fibrosis, and increased cardiomyocyte cross-sectional area. Cardiac injury was accompanied by an increase in the senescence markers SA-β-gal, p16 and p21, and DNA damage marker γH2AX. Moreover, the mRNA levels of p21 increased on day 10, along with several SASP factors, whereas the mRNA levels of p16 increased on day 28. Fibrosis, hypertrophy, and senescence persisted until day 28, indicating long-lasting cardiac remodeling and senescent cell accumulation. Conclusions: These findings suggest that ISO can provide a simple, cost-effective platform for studying senescence and cardiac injury. This model facilitates the study of timing, dosage, mechanisms and efficacy of senolytic interventions and may contribute to the development of senescence-targeted therapies.