观察了低能量5-氨基乙酰丙酸介导的光动力学疗法(ALA-PDT)对脑组织新生血管形成和胶质瘤生长的影响。用10 J/cm2的ALA-PDT照射27只裸小鼠大脑皮层后第1、5、10天，利用二维、三维图像观察新生血管形成，western blot检测缺氧诱导因子-1α(HIF-1α)和血管内皮生长因子(VEGF)表达。另将12只裸小鼠分为对照组(无特殊处理)和ALA-PDT预处置组(10 J/cm2)，ALA-PDT预处置后第10天，颅内接种U87胶质瘤细胞，21天检测肿瘤体积。结果发现，以照射区对侧大脑相应区域为对照，低能量ALA-PDT照射后第1和5天，血管形态无明显变化，第10天有新生血管形成；VEGF在照射后第5和10天显著增高；HIF-1α在照射后第1天即开始增高，随后越发明显。低能量ALA-PDT可通过HIF-1α诱导VEGF高表达和新生血管形成，这种微环境的改变有助于U87脑胶质瘤细胞的生长。

Effects of 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) with low energy on intracranial angiogenesis and glioma growth are evaluated. Twenty seven nude mice are received low energy of ALA-PDT (ALA: 300 mg/kg, dose: 10 J/cm2) on the right side of the cerebral cortex. After 1、5、10 days, angiogenesis is evaluated by 2 and 3 dimensional vessel images, and expressions of VEGF and hypoxia-inducible factor-1α (HIF-1α) by western blot. Other 12 nude mice are divided into control and ALA-PDT (10 J/cm2) pretreated groups. Ten days after pretreatment, mice are implanted intracerebral U87 glioma; and tumor volume is calculated by H.E staining after 21 days. Results show that the vessels in the contralateral brain are as control. Both 2 and 3 dimensional vessel images shown that there is no difference in the microvessels morphology on the first and fifth days after ALA-PDT compared with control. However, there is angiogenesis on the tenth days showing as decreased length, increased diameter and the number of branch points. VEGF expression significantly increased on fifth day and becomes higher on the tenth days after ALA-PDT, although there is no change on the first day; while HIF-1α expressions increased on the first day and become higher and higher. ALA-PDT with low energy can induce VEGF expression and intracerebral angiogenesis mediated by HIF-1α, and this effect promotes glioma growth in brain.