ORIGINAL ARTICLE (Endo)cannabinoids mediate different Ca2+ entry

Abstract In human bronchial epithelial (16HBE14o−) cells, CB1 and CB2 cannabinoid receptors are present, and their activation by the endocannabinoid virodhamine and the synthetic non-selective receptor agonist CP55,940 inhibits adenylyl cyclase and cellular interleukin-8 release. Here, we analyzed changes in intracellular calcium ([Ca2+]i) evoked by Δ9-tetrahydrocannabinol (Δ9-THC), CP55,940, and virodhamine in 16HBE14o − cells. Δ9-THC induced [Ca2+]i increase and a large transient [Ca 2+]i mobilization, the latter probably reflecting store-depletion-driven capaci-tative Ca2+ entry (CCE). In contrast, CP55,940 induced a rather moderate Ca2+ influx and a sustained [Ca2+]i mobilization. CP55,940-induced Ca2+ influx was inhibited by Ni2+, indicating CCE, possibly mediated by transien