摘要Objective: To evaluate plasma arginine vasopressin (AVP) level in patients with traumatic brain injury and investigate the role of AVP in the process of brain edema. Methods: A total of 30 patients with traumatic brain injury were involved in our study. They were divided into two groups by Glasgow Coma Scale: severe traumatic brain injury group (STBI, GCS≤ 8) and moderate traumatic brain injury group (MTBI, GCS＞8).Samples of venous blood were collected in the morning at rest from 15 healthy volunteers (control group)and within 24 h after traumatic brain injury from these patients for AVP determinations by radioimmunoassay. The severity and duration of the brain edema were estimated by head CT scan.Results: plasma AVP levels (ng/L) were (mean±SD): control, 3.06±1.49; MTBI, 38.12±7.25; and STBI, 66.61±17.10.The plasma level of AVP was significantly increased within 24 h after traumatic brain injury and followed by the reduction of GCS, suggesting the deterioration of cerebral injury (P＜0.01). And the AVP level was correlated with the severity (STBI r=0.919, P＜0.01; MTBI r=0.724, P＜0.01) and the duration of brain edema (STBI r=0.790, P＜0.01; MTBI r=0.712, P＜0.01). Conclusions: The plasma AVP level is closely associated with the severity of traumatic brain injury. AVP may play an important role in pathogenesis of brain edema after traumatic brain injury.