OBJECTIVE: To summarize the effects of glial cell line-derived neurotrophic factor (GDNF) on ischemia damage to nerve tissue and discuss the possibility of GDNF in repair of spinal cord injury based on the development of microencapsulation technology.DATA SOURCES: A search of Medline from January 1996 to October 2000 was performed for the English articles related to GDNF, ischemia damage to nerve tissue, spinal cord injury and microencapsulation technology by using the key words "glial cell line-derived neurotrophic factor, ischemia damage to nerve tissue, spinal cord injury". Meanwhile, we retrieved Wangfang database for search of the related articles in Chinese by using the same keywords in Chinese.STUDY SELECTION: Articles including intervention group and control group were selected after first review, and those which were significantly non-randomized researches were excluded. Then, the full-texts of the enrolled articles were retrieved. Inclusion criteria: ①randomized controlled study; ②the experiment/clinical research including horizontal control group. Exclusion criteria: duplicated researches.DATA EXTRACTION: Totally 300 articles were selected but only 15 were in coincidence with conclusion criteria. 285 articles were excluded, 264 of them were duplicated and non-randomized researches, and 21 were review articles.DATA SYNTHESIS: GDNF can provide nutrition to dopamine nerve cell in rat's middle brain, so as to decrease dopamine nerve cell's death. Also GDNF can protect dopamine nerve cell in cerebral infarction rats from ischemic injury, inhibit the produce of nitrogen monoxide and reperfusion injury after ischemia. GDNF is an effective protective factor against ischemia damage. Microencapsulation technology has a bright future in treating endocrinopathic neural diseases, and GDNF can play a great role in the development of microencapsulation technology.CONCLUSION: GDNF is a protective factor against ischemia damage to nerve tissue, which can be enhanced by microencapsulation technology.There is a bright future for the research on GDNF in the clinical repair of spinal cord injury.