PERIPHERAL AND CENTRAL EFFECTS OF DAPT IN OROFACIAL INFLAMMATORY PAIN

Mi-Suk Cho*

ABSTRACT

The aim of this study was to investigate whether peripheral and central administration of DAPT, Notch singnaling inhibitor, is involved in pain modulation in inflammatory orofacial pain. The inflammatory orofacial pain was induced by the injection of 5% formalin into right vibrissa pad of rats. The pain behavioral response was measured the number of grooming or scratching on the orofacial area for 9 successive 5 minutes intervals. DAPT was administrated into the identified vibrissa pad(500, 1250, 2500 μM/ 50㎕) or intracisternal space(5, 50, 500 μM/ l0㎕) 10 min before formalin injection. The nociceptive responses were reduced in the 2nd phase (11∼45 minutes), particularly 20, 30 minutes after formalin injection following administration of DAPT into vibrissa pad (1250, 2500 μM/ 50㎕). Intracisternal (5, 50μM/ l0㎕) administration of DAPT alleviated the formalin-induced pain behaviors in the 2nd phase, especially 25∼40 minutes after formalin injection. Therefore, DAPT could be a promising analgesic agent in the treatment of inflammatory orofacial pain.

Keywords: DAPT, Notch signaling, Orofacial pain.