Figure 4
Receptor specificity of PACAP-induced PRL promoter activity in αT3-1 Cells. αT3-1 cells were transiently transfected with pPRL(−1156).LUC for 6 h by using lipofectamine. The cells were then cultured for 18 hr recovery before drug treatment. (A) Time course analysis on the effect of oPACAP38 (6–48 hrs) on grass carp PRL promoter activity in αT3-1 cells. (B) αT3-1 cells over-expressed pPRL(−1156).LUC were treated for 24 hrs with increasing doses of oPACAP38. Effects of PACAP and VIP antagonists on PACAP-induced PRL mRNA expression were also investigated. In these experiments, αT3-1 cells over-expressed pPRL(−1156).LUC were challenged with oPACAP38 (10 nM, 24 hr) in the presence or absence of (C) the PACAP antagonist PACAP6-38 (10 nM) or (D) VIP antagonist (4-Cl-D-Phe6, Leu17)VIP (“VIP-R antagonist”, 100 nM). After drug treatment, cell lysate was prepared for dual-luciferase measurement. Data presented were expressed as percentage of control by conversing the ratio of firefly and renilla luciferase in the same sample. Data presented are expressed as mean ± SEM (n = 4) and different letters denote a significant difference at p < 0.05 (ANOVA followed by Fisher’s LSD Test).
