CB1 Receptors Mediated Inhibition of ATP-Induced [Ca(2+)]i Increase in Cultured Rat Spinal Dorsal Horn Neurons.

CB1 Receptors Mediated Inhibition of ATP-Induced [Ca(2+)]i Increase in Cultured Rat Spinal Dorsal Horn Neurons. Neurochem Res. 2017 Nov 10;: Authors: Long J, Lei X, Chen M, Yang S, Sun T, Zeng J, Yu D, Tian H, Liu X Abstract Spinal cannabinoid receptor 1 (CB1R) and purinergic P2X receptors (P2XR) play a critical role in the process of pathological pain. Both CB1R and P2XR are expressed in spinal dorsal horn (DH) neurons. It is not clear whether CB1 receptor activation modulates the function of P2X receptor channels within dorsal horn. For this reason, we observed the effect of CP55940 (cannabinoid receptor agonist) on ATP-induced Ca(2+) mobilization in cultured rat DH neurons. The changes of intracellular calcium concentration ([Ca(2+)]i) were detected with confocal laser scanning microscopy using fluo-4/AM as a calcium fluorescent indicator. 100 μM ATP caused [Ca(2+)]i increase in cultured DH neurons. ATP-evoked [Ca(2+)]i increase in DH neurons was blocked by chelating extracellular Ca(2+) and P2 purinoceptor antagonist PPADS. At the same time, ATP-γ-S (a non-hydrolyzable ATP analogue) mimicked the ATP action, while P2Y receptor agonist ADP failed to evoke [Ca(2+)]i increase in cultured DH neurons. These data suggest that ATP-induced [Ca(2+)]i elevation in cultured DH neurons is mediated by P2X receptor. Subsequently, we noticed that, in cultured rat DH neurons, ATP-induced Ca(2+) mobilization was inhibited after pretreated with ...
Source: Neurochemical Research - Category: Neuroscience Authors: Tags: Neurochem Res Source Type: research