Early blood-brain barrier disruption after gamma irradiation in rats / 第二军医大学学报

ABSTRACT

Objective: To study the effect of gamma irradiation on the permeability of the blood brain barrier(BBB) in rat brains. Methods:The right caudate nucleuses of Sprague Dawley rats were irradiated by OUR XGD gamma units.Maximum dosages of 20,50,75 and 160 Gy were given using a 4 mm collimator.Immunohistochemistry with antibody of serum albumin was used for detecting the extravasation of endogenous serum components.Ultrastructural changes of BBB were observed through injection of lanthanum nitrate into blood vessels. Results: Extravasation of albumin and BBB opening in the right caudate nucleuses were detected as early as 12 h after irradiation at 50,75 and 160 Gy,and were detected 1 d after irradiation at 20 Gy.Immunoreactivity and emematous water reached their maximum after 3 d, gradually decreased during the following few days,and disappeared by day 7(20,50 Gy) or day 14(75 Gy).Irradiation at 160 Gy elicited persistent extravasation of albumin and BBB opening for 14 d. Conclusion: These are transient impairments to BBB after irradiation at 20,50,75 Gy,and persistent impairments after irradiaton at 160 Gy.