Figure 5

(1DMe)NPYF enhances the DOR agonist induced inhibition of forskolin stimulated cAMP accumulation in the CHO-cells expressing MYChDOR. A. The %-cAMP inhibition was calculated relative to the amount of cAMP in the cells treated with only forskolin. The cells were treated at 37°C for the indicated times with 10 μM forskolin together with 100 nM DPDPE (dashed bars), with 100 nM DPDPE + 100 nM (1DMe)NPYF (black solid bars) or with 100 nM (1DMe)NPYF (white solid bars). The bars next to each treatment at each time-point represent the cells pre-treated with pertussis toxin (+PTX). The statistical significance between treatments and time-points is shown in the figure (two-way ANOVA with Bonferroni's post test, variance as SD; significance relative to forskolin only treated cells ***p < 0.001; significance between treatments ^††p < 0.01, n = 6). B. The effect of (1DMe)NPYF dose on the DPDPE-induced cAMP-inhibition. The cells were stimulated at 37°C for 30 min with 10 μM forskolin together with 0.1 nM – 10 μM DPDPE and 0 nM – 1 μM (1DMe)NPYF. (1DMe)NPYF caused a significant increase in the DPDPE-induced inhibition of cAMP (two-way Anova, variance as SD; DPDPE p < 0.001; (1DMe)NPYF p < 0.001, [DPDPE] × [(1DMe)NPYF p < 0.01, n = 3). The post-hoc test showed that 10 nM (p < 0.05) and 100 nM (p < 0.05) (1DMe)NPYF had a significant effect on the DPDPE induced cAMP inhibition. The solid circles with thick line represent the cells treated with 0.1 nM – 10 μM DPDPE alone, the open triangles cells treated with DPDPE together with 10 nM (1DMe)NPYF, and the solid squares cells treated with DPDPE together with 100 nM (1DMe)NPYF. C. 1 nM (1DMe)NPYF and 1 μM had only minor effects on the DPDPE induced cAMP inhibition. The solid circles with thick line represent the cells treated with 0.1 nM – 10 μM DPDPE alone, the solid triangles cells treated with DPDPE together with 1 nM (1DMe)NPYF and the open squares DPDPE together with 1 μM (1DMe)NPYF.