Table 1.

A summary of the functional rivalry between CB1 and CB2 receptors in myocardial injuries.

Category	CB1 Function	CB2 Function	References
Myocardial infarction	CB1 aggravated cardiac ischemic injuries	CB2 mitigated cardiac ischemic injuries	[20,23,26,27,28]
Cardiac I/R injury	Majority of the literature documents CB1 as a mediator of I/R injury, although there is some controversy across studies	CB2 potently protected from I/R injury	[29,30,31,32,33,34,35,36,37]
Pathological cardiac hypertrophy	Majority of the literature documents CB1 as a pro-hypertrophic receptor, and CB1 tended to be not as potent as CB2 in controlling hypertrophy	CB2 potently conferred anti-hypertrophic property	[38,39,40]
Cardiac fibrosis	CB1 promoted fibrogenesis mainly through TGF-β1/Smad3 pathway	CB2 ameliorated cardiac fibrosis via TGFβ1-dependent and independent manners	[23,27,29,30,40,41,42,43,44,45,46]
Antipsychotics cardiotoxicity	Pharmacological inhibition of CB1 was cardioprotective	Pharmacological activation of CB2 was cardioprotective	[47,48,49,50]
Anti-tumor drug cardiotoxicity	Genetic ablation or pharmacological antagonism of CB1 was cardioprotective	Unknown	[51,52]
Ethanol-induced myocardial injury	Less known	CB2 attenuated ethanol toxicity	[53,54]