Figure 2. MT1 andMT2 melatonin receptors mediate melatonin-induced StAR expression in primary hGL cells. Cells were pre-treated with vehicle control (DMSO), 10 μM 4-P-PDOT, or 10 μM luzindole for 30 min and then exposed to 500 μM melatonin for 24 h. StAR mRNA (A) and protein (B) levels were examined by RT-qPCR and western blot, respectively. Results are expressed as the mean ± SEM of 4 independent experiments. Values without a common letter are significantly different (p < 0.05).