The Effects of Regulating Increased Blood Glucose Levels on Plasma Endothelin-1 Levels After Severe Head Trauma in Rats.

Abstract

Aim: To examine the effects of regulating increased blood glucose levels on plasma ET-1 levels after severe head trauma in rats.

Material and methods: Traumatic diffuse brain injury-induced rats were followed for 7 days and were randomly divided into two groups of 36 rats. Pre- and posttraumatic blood glucose and ET-1 levels were measured in group 1 (control). Posttraumatic blood glucose levels were maintained at normal levels using insulin and both blood glucose and ET-1 levels were measured at 2, 6, 12, 24, and 48 h and 7 days posttrauma in group 2. The study excluded animals that died and had skull fractures.

Results: Posttraumatic plasma ET-1 levels (n=36) were significantly higher than baseline values in group 1 (p < 0.05). ET-1 levels in group 2 at the 7-day follow-up after trauma were significantly higher than baseline values (n=36) (p < 0.05). However, the increased ET-1 levels were statistically significantly lower in group 2 than in group 1 (p < 0.05).

Conclusion: The increased ET-1 levels were significantly prevented by keeping blood glucose levels within normal limits with insulin after severe head trauma. Thus, secondary injury to cerebral blood flow can be prevented by reducing the occurrence of vasospasm that starts in the early posttraumatic period or by stimulating the release of nitric oxide. Therefore, further studies on the role of ET-1 and insulin in developing secondary injuries after severe head trauma would be beneficial.