Fig. 1
From: Cannabinoid-based drugs targeting CB1 and TRPV1, the sympathetic nervous system, and arthritis
Effects of CB1 activation or inhibition on norepinephrine (NE) release in tissue. CB1 regulates the amount of NE released from sympathetic nerve terminals. The red zone depicts the effects of CB1 agonism, which decreases NE release. Only cells within the red line boundary can be modulated by β-adrenergic receptors under CB1 activation. Beyond the dotted 'β-adrenergic zone', α-adrenergic effects prevail. Under basal conditions, the β-adrenergic area is increased (black dotted line). Under CB1 inhibition, NE release is boosted and maximal β-adrenergic effects can be achieved (green dotted line). Beta receptor activation on immune cells decreases production of pro-inflammatory mediators, for example, tumor necrosis factor