Study of antinociceptive effect of ketamine in acute and neuropathic pain models in rats

Abstract

Background. Glutamate N-methyl-D-aspartate (NMDA) receptors are known for their importance in the perseverance of chronic neuropathic pain. Ketamine, an intravenous anesthetic agent, is a non-competitive blocker of NMDA receptors. Applied in anesthetic doses, ketamine has anti-nociceptive effects in various animal pain models. Objectives. The objective of this study was to investigate the anti-nociceptive effect of ketamine in acute and neuropathic pain models in rats. Material and methods. To study the anti-nociceptive effect of ketamine on acute pain, 40 Wistar rats were divided into 5 groups (n = 8): control, positive control group and 3 experimental groups treated intraperitoneally (ip.) with 30 mg/kg bw, 40 mg/kg bw and 50 mg/kg bw ketamine, respectively. The anti-nociceptive effect was evaluated in hot plate, analgesy-meter and formalin tests. The model of neuropathic pain was induced by left sciatic nerve ligation. Twenty-four Wistar rats were divided into 3 groups (n = 8): sham-control group, model group and ketamine-treated group subsequently tested in hot plate and analgesy-meter tests. Results. In the hot plate test, the rats treated with ketamine presented increased reaction latency at the 120 th min and 180 th min compared to the controls. In the analgesy-meter test, ketamine produced an antinociceptive effect at the 60 th min compared to the controls. In the formalin test, the paw licking time across the early phase of testing was reduced in the rats treated with the 2 higher doses of ketamine. In a neuropathic pain model, ketamine increased the reaction latency at the 120 th min and 180 th min compared with the model group in the hot plate test. In the analgesy-meter test, in the ketamine-treated animals the paw withdrawal threshold increased at the 60 th min compared with the model group. Conclusions. Our results suggest that ketamine produces peripheral anti-nociceptive effect in an acute pain model. Also, it relieves thermal and mechanical allodynia after 14 days of treatment in a neuropathic pain model.

Preemptive effect of amantadine as adjuvant in postoperative analgesia of ovaryhisterectomy in dogs

“…In this study, the DIVAS scores in the group treated with amantadine were significantly lower than those in the control group. This result is consistent with those of previous studies in which other NMDA receptor antagonists reduced postoperative pain from thoracotomy in humans (Moyse et al, 2017) and demonstrated antinociceptive effect in rats (Wolinska et al, 2017;Doncheva et al, 2019) and in dogs undergoing ovariohysterectomy (Slingsby and Waterman-Pearson, 2010;Almeida et al, 2013;Shah et al, 2018).…”

Pain Modulation in WAG/Rij Epileptic Rats (A Genetic Model of Absence Epilepsy): Effects of Biological and Pharmacological Histone Deacetylase Inhibitors

“…The cut-off imposed was 30 s to avoid tissue damage. The reaction time was subsequently assessed 1-6 months after chronic oral treatments (Doncheva et al, 2019). The data were collected by an observer who was blinded to the protocol.…”

The effects of intrathecal ketamine on improving sensory-motor function in a rat model of compression spinal cord injury

“…Further, a meta-analysis showed that KET analgesic effect persists for at least 4 weeks (Niesters et al, 2014), which was in line with the long-lasting impact of KET in our study. Despite the long-lasting effects of IT KET on sensory-motor dysfunction, Doncheva et al (2019) found that 14-day IP injection of KET showed an early and short-lasting analgesic effect in a rat model of sciatic nerve ligation as evaluated by formalin, analgesia-meter and hot plate tests. In the current study, pain and motor performance were assessed from the 7 th day to 28 th day post-injury.…”