Elena Kaschina

By Elena Kaschina

Endocannabinoids exert their actions in the heart and vessels, at least in part, by stimulating the cannabinoid CB1 and the CB2 receptor subtypes which belong to a group of seven transmembrane-spanning receptors and are coupled to Gi/o-proteins. Activation of cardiovascular CB1 receptors leads to depressed cardiac contractility and hypotension. Conversely, in most studies, the CB1 receptor antagonists are cardioprotective against ischemia–reperfusion injury, myocardial ischemia, heart failure, and cardiomyopathies. Evidence to date indicates that CB2 receptor activation is cardioprotective. CB2 receptor-mediated effects such as anti-inflammation and anti-fibrosis may be in part opposite to the actions of the CB1 receptor. The aim of this review is to up-date on recent experimental findings and controversies on the role of endocannabinoid system in the myocardial injury with emphasis on pathophysiological processes such as left ventricular remodeling, cardiac fibrosis, hypertrophy, and endothelial dysfunction. Recent experimental studies employing genetic deficiency of CB1 and CB2 receptors and endocannabinoid anandamide metabolizing enzymes are reviewed. Moreover, the protective mechanisms which are mediated by cannabinoid receptors during ischemic preconditioning as well as in the early and late phase after myocardial infarction are discussed in the context of possible therapeutic implications.

Part of the book: Cannabinoids in Health and Disease