Effects of Kyotorphin and D-Kyotorphin on Pain Perception and Blood ACTH and Corticosterone Concentrations after Heat Stress in Rats

Adriana Bocheva, Hristina Nocheva, Dimo Krastev

Abstract: Aims & Objectives: The present study consists in evaluation of the effects of the dipeptides Kyotorphin (Kyo) and D-Kyotorphin (D-Kyo) on nociception and plasma levels of adrenocorticotrophic hormone and corticosterone after 1 hour of heat stress in rats. Materials & Methods: Kyo and D-Kyo`s effects on nociception were evaluated by Paw pressure and Hot plate test after 1 hour of heat stress. Plasma levels of both hormones were determined by Radio immunological assays. Conclusions: Since a decrease in heat-stress-induced analgesia and ACTH and CORT plasma levels was observed we assumed that both dipeptides take part in the body`s anti-stress system.

Keywords: Kyotorphin, D-Kyotorphin, Heat stress, Nociception, Anti-stress system