Role of endocannabinoids and endovanilloids in Ca2+ signalling

Endocannabinoids and endovanilloids are, by definition, endogenous agonists at cannabinoid CB1 or CB2 receptors and transient receptor potential vanilloid-type-1 (TRPV1) channels, respectively. Due to the several ways through which cannabinoid receptors influence cytosolic Ca2+ concentrations, and to the fact that TRPV1 activation leads to the gating of cations, including Ca2+, both endocannabinoids and endovanilloids, taken separately, can strongly influence Ca2+ signalling. Moreover, CB1/CB2 receptors and TRPV1 channels are often expressed in the same or neighbouring cells, and this can lead to cross-talk between the two receptor types, which is further enriched by the fact that some endocannabinoids, like anandamide and N-arachidonoyidopamine, also activate TRPV1 channels. Finally, both endocannabinoids and endovanilloids also interact with non-cannabinoid, non-TRPV1 receptors and channels, and, although the full physiological relevance of such interactions is yet to be established, the "promiscuity" of these lipophilic molecules can increase even further the potential ways through which they affect Ca2+ signalling. Here we discuss the effects of endocannabinoids and endovanilloids on cytosolic Ca2+ concentrations and their potential biological consequences. (C) 2009 Elsevier Ltd. All rights reserved.