CNR1 and cardiac hypertrophy: In this regard, our group has found that cannabinoid receptor (CBR) ligands exert cardioprotective effects in ventricular hypertrophy models in vitro and in vivo presumably due to activation of AMPK (Lu et al., 2014; Lu et al., 2020) Recently, we also demonstrated that CB13, a dual CBR agonist with limited brain penetration, is an AMPK activator that prevents tachycardia-induced electrical remodeling and improves energy metabolism in the rat atria ex vivo (Lee et al., 2021).