Arachidonic acid mediates non-capacitative calcium entry evoked by CB1-cannabinoid receptor activation in DDT1 MF-2 smooth muscle cells.

Cannabinoid CB1-receptor stimulation in DDT1 MF-2 smooth muscle cells induces a rise in [Ca2+]i, which is dependent on extracellular Ca2+ and modulated by thapsigargin-sensitive stores, suggesting capacitative Ca2+ entry (CCE), and by MAP kinase. Non-capacitative Ca2+ entry (NCCE) stimulated by arachidonic acid (AA) partly mediates histamine H1-receptor-evoked increases in [Ca2+]i in DDT1 MF-2 cells. In the current study, both Ca2+ entry mechanisms and a possible link between MAP kinase activation and increasing [Ca2+]i were investigated.