a Departments of Neurobiology and Anatomy and.
Radiat Res. 2013 Sep;180(3):326-33. doi: 10.1667/RR3313.1. Epub 2013 Aug 16.
Cranial irradiation is a critical and effective treatment for primary brain tumors and metastases. Unfortunately, most patients who are treated and survive for more than a few months develop neural and cognitive problems as the result of radiation-induced normal tissue injury. The neurobiological mechanisms underlying these cognitive deficits remain largely unknown and there are no validated treatments to prevent or ameliorate them; thus, there is a significant and continuing need for preclinical studies in animal models. Investigations from several laboratories have demonstrated neurobiological changes after cranial irradiation in rodents. To date, however, experimental studies in animal models have included little assessment of the systemic effects of cranial irradiation, despite evidence from the clinic that cranial irradiation results in changes throughout the body and recognition that systemic responses may influence the development of neural and cognitive deficits. This study evaluated systemic effects of clinically relevant, fractionated whole-brain irradiation in adult rats and demonstrates effects on the growth hormone/insulin-like growth factor-I axis, which may contribute to the development of neural changes. These and other systemic responses are important to consider in ongoing efforts to understand the mechanisms of radiation-induced normal tissue injury.
颅脑照射是治疗原发性脑肿瘤和转移瘤的关键且有效的方法。不幸的是，大多数经过治疗并存活数月以上的患者都会因辐射引起的正常组织损伤而出现神经和认知问题。这些认知缺陷的神经生物学机制在很大程度上尚不清楚，也没有经过验证的治疗方法来预防或改善它们；因此，在动物模型中进行临床前研究具有重要意义且仍在继续。几个实验室的研究表明，在啮齿动物中颅脑照射后会发生神经生物学变化。然而，到目前为止，动物模型中的实验研究几乎没有评估颅脑照射的全身效应，尽管临床证据表明颅脑照射会导致全身发生变化，并认识到全身反应可能会影响神经和认知缺陷的发展。本研究评估了成年大鼠临床相关的、分次全脑照射的全身效应，并证明了其对生长激素/胰岛素样生长因子-I 轴的影响，这可能导致神经变化的发生。这些和其他全身反应在理解辐射引起的正常组织损伤的机制的持续努力中是重要的考虑因素。
