Animal studies have shown that titanium dioxide (TiO₂) exposure affects arterial vasomotor function, whereas little is known about the effects in arteries from humans. This study investigated vasomotor responses after direct exposure of human subcutaneous arteries to food-grade TiO₂ (E171) (14 or 140 μg/ml) for 30 min and 18 h. Vasomotor responses to bradykinin, 5-hydroxytryptamine (5-HT), sarafotoxin 6c (S6c) and nitroglycerin were recorded in wire-myographs. Vasoconstrictor responses to 5-HT were increased in arteries exposed to E171 for 18 h (P < 0.05). Furthermore, an increase in S6c responses was seen in low concentration E171 exposed arteries (30 min exposure; P < 0.05). The vasorelaxation response to nitroglycerin was increased in low concentration E171 exposed arteries (30 min exposure; P < 0.05). Vasorelaxation responses to bradykinin were unaffected after treatment with E171. There was no difference in gene expression levels of intercellular cell adhesion molecule 1, vascular cell adhesion molecule 1, 5-hydroxytryptamine receptor 1B, 5-hydroxytryptamine receptor 2A, endothelin receptor A and endothelin receptor B in E171 exposed arteries after exposure to TiO₂ for 30 min or 18 h. In conclusion, this study shows that the same type of vasomotor dysfunction is found in artery segments of rats and humans following ex vivo exposure to E171.

动物研究表明，二氧化钛（TiO ₂）暴露会影响动脉血管舒缩功能，而人类对动脉血管的作用知之甚少。这项研究调查了人类皮下动脉直接暴露于食品级TiO ₂（E171）（14或140μg/ ml）30分钟和18小时后的血管舒缩反应。钢丝肌电图记录了对缓激肽，5-羟色胺（5-HT），sarafotoxin 6c（S6c）和硝酸甘油的血管舒缩反应。在暴露于E171 18 h的动脉中，对5-HT的血管收缩反应增加（P  <0.05）。此外，在低浓度E171暴露的动脉（暴露30分钟；P <0.05）。在低浓度E171暴露的动脉中（30分钟暴露；P  <0.05），对硝酸甘油的血管舒张反应增加。用E171治疗后，对缓激肽的血管舒张反应不受影响。暴露于TiO _2的E171暴露的动脉中，细胞间细胞粘附分子1，血管细胞粘附分子1，5-羟色胺受体1B，5-羟色胺受体2A，内皮素受体A和内皮素受体B的基因表达水平没有差异。 30分钟或18小时。总之，这项研究表明，离体暴露于E171后，在大鼠和人的动脉节段中发现了相同类型的血管舒缩功能障碍。