Tacconi M T
Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy.
Neurochem Res. 1998 May;23(5):759-65. doi: 10.1023/a:1022463527474.
Astrocytes are ubiquitous in the brain and have multiple functions. It is becoming increasingly clear that they play an important role in monitoring the neuromicroenvironment in CNS and in information processing or signaling in the nervous system in normal conditions and respond to CNS injuries in a gradual and varied way. It is still debated whether such reactions are beneficial or detrimental. It was believed that reactive astrogliosis observed in most neurological disorders may regulate the removal of toxic compounds produced by damaged neurons and support neuronal growth by releasing trophic factors. However it was also suggested that astrocytes contribute to a decline of neurologic function, for example by accumulation and release of excitotoxic aminoacids after ischemia and oxidative stress, formation of epileptogenic scars in response to CNS injury and metabolism of protoxins to potent toxins. In a number of metabolic diseases astrocytes, not neurons, may be the primary target. The astrocyte's role in normal and pathological conditions will be discussed in the light of recent information about their metabolism, receptor distribution and release.
星形胶质细胞在大脑中广泛存在且具有多种功能。越来越清楚的是，它们在监测中枢神经系统的神经微环境、正常情况下神经系统的信息处理或信号传导中发挥着重要作用，并以渐进和多样的方式对中枢神经系统损伤做出反应。这种反应是有益还是有害仍存在争议。人们认为，在大多数神经系统疾病中观察到的反应性星形胶质细胞增生可能通过释放营养因子来调节受损神经元产生的有毒化合物的清除，并支持神经元生长。然而，也有人提出星形胶质细胞会导致神经功能下降，例如在缺血和氧化应激后通过兴奋性毒性氨基酸的积累和释放、对中枢神经系统损伤的反应中形成致痫性瘢痕以及将原毒素代谢为强效毒素。在许多代谢性疾病中，星形胶质细胞而非神经元可能是主要靶点。将根据有关星形胶质细胞代谢、受体分布和释放的最新信息来讨论其在正常和病理条件下的作用。
