Abstract

Background: G protein couple receptor kinase 2 and 5 (GRK2 and GRK5) are the main negative regulator for β-adrenoreceptor activation, which play an important role in cardiac function and
contractility. Up-regulation in GRK2 levels has been found play an important role in cardiac hypertrophy development. However, little is known about whether GRK5 modulates Isoproterenol
induced cardiac hypertrophy and the change in protein level of GRK5 in animal model of cardiac hypertrophy is not well elucidated yet. Aim: This research aims to investigate the change in
GRK5 protein expression in Isoproterenol -induced cardiac hypertrophy animal model. Method: Cardiac hypertrophy was induced in rats by daily Intraperitoneal injection of Isoproterenol
(5mg/kg/day). After three weeks, cardiac hypertrophy biomarkers were assessed. GRK5 protein expression were detected using western blotting and immunohistochemistry techniques. Results:
Key findings data showed that serum creatinine, troponin T and heart weight/ body weight ratio significantly increased in cardiac hypertrophic rats. Furthermore, a significant up-regulation in
GRK5 protein expression was observed in hypertrophic myocardium tissue. Conclusion: Our research yielded promising results verifying a strong link between animal model cardiac
hypertrophy and an over expression of GRK5. Our results suggest that over-expression of GRK5 in animal model of cardiac hypertrophy might play an important role in pathological cardiac
hypertrophy development. Furthermore, over-expressed GRK5 could be suggested as new marker to investigate cardiac hypertrophy development or as potential therapeutics target.