Effects of intrathecal carbenoxolone treatment on nociception and analgesia in rat

Abstract

Background: Gap junctions (GJ) are important in pain signalling at the spinal cord level. Aims: The aim of this investigation was to study the effects of GJ on nociception and the analgesic/hyperalgesic effects of mor­phine fol- lowing administration of carbenoxolone as a GJ blocker. Male Wistar rats (200-250 g) were divided into three groups: saline i.p., 10 mg/kg and 1 μg/kg i.p. morphine, each with two subgroups. One was treated intrathecally with saline and the other with carben­oxolone.Study Design: Animal experiment. Methods: The thermal nociception threshold was measured prior to and after injections using the tail flick test. Chemical nociception assessment was conducted using a 0.05-mL subplantar injection of 2.5% formalin. Results: Both formalin-induced neurogenic and inflammatory noci- ception were reduced in the [saline i.p./carbenoxolone i.t.] and [mor- phine 1 μg/kg, i.p./carbenoxolone i.t.] subgroups (p