Figure 4

Induction of dopamine D3 and D4 receptor mRNA levels in SK-NF-I cells upon hypoxia. Parallel cultures of SK-NF-I cells were maintained under normoxic or hypoxic conditions for the indicated time periods. Cells were harvested, total mRNA was isolated and analyzed in real-time reverse transcription PCR assays with TaqMan probes specific for the human DRD2 (circles), DRD3 (triangles) and DRD4 (squares) receptors. VEGF (filled circles) was included as a well-known control target gene of HIF-1α. Expression levels were normalized to the RPLP0 internal control gene. All data are expressed as fold changes relative to levels measured in parallel normoxic samples. Data are means of three parallel determinations from three independent experiments (N = 9); bars represent standard deviations (*: p < 0.05; **: p < 0.01 and ***: p < 0.001).