Effect of nitrotyrosine on the expression of α1D-adrenoceptor mRNA in vascular smooth muscle of rat

Objective To investigate the effect of nitrotyrosine (3-NT) on the expression of α1D adrenoceptor (α1D-AR) mRNA in cultured vascular smooth muscle cells (SMCS) .Methods SMCS were obtained from the tunica media of thoracic aorta of 1 month old SD rats and cultured in DMEM medium. The experiment consisted of two parts. In part Ⅰ SMCS were incubated with 0,1, 10, 100 or 200 μmol·L-1 3-NT for 24 h and in part Ⅱ SMCS were incubated with 100 μmol·L-1 3-NT forO,12, 24, 48 or 72 h. The total RNA was isolated by using Trizol reagent. The expression of α1D-AR mRNA was determined by RT-PCR and agarose gel electrophoresis. Results In part I incubation with 1 and 10 μmol·L- 3-NT for 24 h had no significant effect on the expression of α1D-AR mRNA while incubation with 100 or 200 μmol·L-1 3-NT for 24 h decreased the expression of α1D-AR mRNA compared with 0μmol·L-1 3-NT (P 0.05). In part ⅡI incubation with 100 μmol·L-1 3-NT for 12 h did not significantly affect α1D-AR mRNA expression compared with 100 μmol·L-1 3-NT for 0 h, whereas incubation with 100 μmol· L-1 3-NT for 24, 48 and 72 h decreased the expression of α1D-AR mRNA ( P 0.05). Conclusion Our results suggest that 3-NT inhibits the expression of α1D-AR mRNA in SMCS.