Kucuktulu Eda
Department of Radiation Oncology, Trabzon Kanuni Training and Research Hospital, Trabzon, Turkey.
Asian Pac J Cancer Prev. 2012;13(8):4101-5.
The degree of radiation injury to kidneys which are located within the limits of radiotherapy area is determined by the volume and the dose of radiation to which the organ is exposed. When the tolerance dose of the kidney is exceeded after a latent period of 6 months acute nephritis develops and after 18 months chronic nephritis ensues. Melatonin is known to prevent the oxidative injury of toxins and radiotherapy with its free radical scavenging capacity.
In this study 8 weeks old 24 Sprague -Dawley rats were allocated into 4 groups: Control group; Radiotherapy group (20 Gy bilaterally in 5 fractions); Melatonin group (10 mg/kg intraperitoneally), and Melatonin+radiotherapy group (20 Gy Radiotherapy in 5 fractions+ melatonin 10 mg/kg intraperitoneally). After a follow-up period of 6 months BUN was determined in all groups. After rats were euthanized the kidneys were removed for histopathological examination under both light and electron microscopes.
After 6 months follow-up, both at light and electron microscopy levels, the rats in radiotherapy+melatonin group were significantly protected against the radiation injury comparing to radiotherapy group (p<0.05).
It was shown in this experimental model that melatonin has protective effects against radiation injury to kidneys.
位于放疗区域范围内的肾脏所受辐射损伤程度取决于该器官所接受的辐射体积和剂量。在6个月的潜伏期后若超过肾脏的耐受剂量,会引发急性肾炎,18个月后则会导致慢性肾炎。已知褪黑素凭借其清除自由基的能力可预防毒素和放疗造成的氧化损伤。
在本研究中,将24只8周龄的斯普拉格-道利大鼠分为4组:对照组;放疗组(分5次双侧给予20 Gy);褪黑素组(腹腔注射10 mg/kg),以及褪黑素+放疗组(分5次给予20 Gy放疗+腹腔注射10 mg/kg褪黑素)。随访6个月后,测定所有组的血尿素氮。大鼠处死后,取出肾脏在光镜和电镜下进行组织病理学检查。
随访6个月后,在光镜和电镜水平上,与放疗组相比,放疗+褪黑素组的大鼠对辐射损伤均有显著的保护作用(p<0.05)。
该实验模型表明,褪黑素对肾脏辐射损伤具有保护作用。