Effect of naloxone hydrochloride on c-fos protein expression in brain and plasma beta-endorphin level in rats with diffuse brain injury and secondary brain insult / 解放军医学杂志

ABSTRACT

Objective To observe the changes of c-fos protein expression in brain and beta-endorphin (β-EP) level in blood plasma in rats with diffuse brain injury (DBI) and secondary brain insult (SBI) after intraperitoneal injection of naloxone hydrochloride, and explore the role of c-fos and β-EP in development of SBI in rats. Methods Seventy health male SD rats were enrolled in the present study and randomly divided into group A (intraperitoneally injected with 0.9% saline after DBI and SBI model was reproduced), group B (injected intraperitoneally with 1.0mg/kg naloxone hydrochloride after DBI and SBI model was reproduced), and group C (intraperitoneally injected with 1.0mg/kg naloxone hydrochloride after DBI and before SBI model was reproduced). The animals were sacrificed 3, 24 and 48 hours after injury, and the number of c-fos positive cells in brain and content of β-EP in blood plasma were determined by immunohistochemistry and radioimmunoassay respectively, the water content and number of injured neurons in brain tissue were measured by pathomorphological observation of the brain tissue. Results No significant difference was observed between group B and C for all the detection parameters. In group B and C, the water content in brain tissue at 3h and 24h was found to be decreased, while the number of injured neurons at 24h and 48h increased, number of c-fos positive cells in brain at 3h, 24h and 48h decreased, and content of β-EP in blood plasma at 3h and 24h decreased when compared with group A(P<0.05). Conclusion Naloxone hydrochloride could decrease the c-fos expression in brain and β-EP level in blood plasma, alleviate the nerve injury, and protect neural function. The therapeutic effect of naloxone administered either after DBI and SBI or after DBI and before SBI was similar.