Turkish Neurosurgery 1999 , Vol 9 , Num 1-2
EFFECT OF BETA-ENDORPHIN ON PAIN THRESHOLD IN HYPOPHYSECTOMIZED RATS
Alper BAYSEFER1, K. Melih AKAY1, Mehmet DANEYEMEZ1, Yavuz NARİN2, Güzin EVREN3, Naci SEBER1
1Departments of Neurosurgery, Gülhane Medical School, Ankara
2Departments of Nuclear Medicine, Gülhane Medical School, Ankara
3Departments of Pathology, Gülhane Medical School, Ankara
Beta-endorphin (B-EP) is a 31 amino acid polypeptide secreted by the pituitary, brain, and various other tissues. It has potent opiate-like activity, can produce analgesia, and may play a physiological role in adapting the immune system to stress by affecting lymphocyte and complement binding activity. To investigate the effect of B-EP on pain threshold, we analyzed cerebrospinal fluid (CSF) and plasma concentrations of B-EP in 12 intact and 12 hypophysectomized (HYP) rats. Plasma and CSF samples were obtained from both intact and HYP rats 24 hours postsurgery. Pain threshold values were then assessed using the tail-flick test. Results showed a decrease in the plasma concentration of B-EP (p < 0.001), but no significant difference in the level in CSF. Keywords : Beta-endorphin, hypophysectomy, pain threshold, tail-flick test
Corresponding author : Alper Baysever