Figure 6. Opioid-mediated inhibition of TRPM3 is independent of cAMP and Gαi subunits.
(a) Traces showing the effect of 8-bromo cAMP (1 mM) on morphine (10 µM) induced inhibition of [Ca2+]i–responses evoked by PS (20 µM) in DRG neurons. F(340/380) indicates fura-2 emission ratio. (b) Box and whisker and scatter plots displaying the average response amplitudes from experiments such as a., control, n = 96; morphine, n = 95; morphine +8 bromo cAMP, n = 118) ***p<0.001, compared to control. (c) Whole cell recordings illustrating morphine inhibition of PS-evoked outward membrane currents in CHO cells co-expressing TRPM3 and the µ opioid receptor (+60 mV) in the absence (left) and presence (right) of 100 µM NF023 in the pipette solution. (d) Box and whisker and scatter plots showing the percentage inhibition of 50 µM PS-evoked currents in the absence and presence of NF023. No significant difference noted (p=0.1).