Basal levels of MOR, DOR and KOR mRNA in neuronal and immune cell lines
. Basal levels (copy number) of the human MOR, DOR and KOR in the U87 MG astrocytic, HL-60 (TPA differentiated and undifferentiated), NMB, and SH-SY5Y cell lines were determined using absolute quantitative real time RT-PCR (AQ-rt-RT-PCR). GAPDH was used to normalize the levels in each cell line. Data are indicated as the mean ± SE.