Effects of thyroxine and propylthiouracil on nitric oxide synthase expression in human umbilical vein endothelial cells / 中华地方病学杂志

ABSTRACT

Objective:To investigate the effects of thyroxine (T 4) and propylthiouracil (PTU) on nitric oxide synthase expression in human umbilical vein endothelial cells (HUVEC cells). Methods:HUVEC cells were cultured in vitro, the experiment was divided into 6 groups control (without T 4 and PTU), 10 -9, 10 -7, 10 -4 mol/L T 4, PTU (5 μg/ml PTU), and 10 -4 mol/L T 4 + PTU, the action time was 24 h. CCK-8 method was used to detect cell activity; nitrate reductase method was used to detect nitric oxide (NO), total nitric oxide synthase (TNOS) and endothelial nitric oxide synthase (eNOS) contents; Western blotting was used to detect eNOS protein expression level. Results:The differences of cell survival rates [(100.00 ± 0.00)%, (96.73 ± 1.17)%, (86.20 ± 7.54)%, (47.37 ± 9.10)%, (53.37 ± 5.47)%, (53.40 ± 8.84)%] among the 6 groups were statistically significant ( F = 29.42, P < 0.05). Compared with the control group, the cell survival rates of 10 -7, 10 -4 mol/L T 4, PTU, and 10 -4 mol/L T 4 + PTU groups were significantly reduced ( P < 0.05). There were statistically significant differences in the contents of NO and TNOS among the 6 groups ( F = 3.93, 3.46, P < 0.05). Compared with the control group, the TNOS content in PTU group was significantly reduced ( P < 0.05); compared with the 10 -4 mol/L T 4 group, the NO contents in PTU and 10 -4 mol/L T 4 + PTU groups were significantly reduced ( P < 0.05). There were no significant differences in eNOS content and protein expression level among the 6 groups ( F = 0.24, 0.17, P > 0.05). Conclusions:High concentration of T 4 can cause damage to the activity of HUVEC cells cultured in vitro, and PTU can alleviate it by regulating NO and TNOS. The specific mechanism of action still needs to be further studied in molecular biological experiments.