RESUMO
<p><b>OBJECTIVE</b>To explore the effect of the level of lipid peroxidation and biomechanical properties after chronic treating with tetrahydrobiopterin (BH4) in thoracic aorta of hyperlipemia (HL) rats.</p><p><b>METHODS</b>HL rats were given BH4 chronically. The opening angle in the zero-stress state and the relationship between pressure and diameter (P-D) of mesenteric artery were measured by computer image 8, 16, and 24 week-old respectively.</p><p><b>RESULTS</b>Treating with BH4 chronically from 8 week-old in HL rats, there was a significant increase in the zero-stress state of opening angle of thoracic aorta. The P-D curve of mesenteric artery moved upward.</p><p><b>CONCLUSION</b>Treating with BH4 prevented the structure and function of artery from abnormal changing, and attenuated lipid peroxidation in HL rats.</p>