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Does inflammation induced by ultraviolet B and heat rekindling alter pain-related behaviour in rats?

      Abstract

      Objective

      To investigate whether induction of the ultraviolet B and heat rekindling (UVB/HR) model alters burrowing behaviour in rats.

      Study design

      Randomized, blinded, prospective experimental study.

      Animals

      Sixteen adult male Wistar rats weighing 250–300 g.

      Methods

      In the UVB/HR group (n = 8), UV irradiation was delivered to the heel area of the right plantar pelvic limb paw at a dose of 1000 mJ cm−2, using a narrow-band UVB light source. Twenty-four hours later, heat rekindling was performed by placement of a feedback-controlled thermode set at a constant temperature of 45 °C over the area of UVB irradiation for 5 minutes. Both interventions were carried out under pentobarbital anaesthesia. The ‘sham’ group (n = 8) was anaesthetized only. In the burrowing test, rats were housed singly for 2 hours in cages furnished with a burrow filled with sand. The amount of sand remaining in the burrow after 2 hours was weighed and the amount displaced from the burrow calculated. The burrowing test was carried out for two consecutive days prior to UVB irradiation (day 0), on day 1 prior to HR, on days 2 and 3 after UVB exposure and at equivalent time points in the sham group.

      Results

      Rats in the sham group burrowed means (SD) of 2429 (73) g and 2358 (124) g of sand on days −2 and 3, respectively, while those in the UVB/HR group burrowed 2460 (26) and 2419 (58) g on days −2 and 3, respectively. There was no significant effect of treatment on the amount of sand burrowed at any time point.

      Conclusions and clinical relevance

      Pain associated with UVB/HR model induction is below the threshold required to affect rat burrowing behaviour and therefore questions the face validity of UVB/HR as a translational model of inflammatory pain.

      Keywords

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      References

        • Andrews N
        • Harper S
        • Issop Y
        • et al.
        Novel, nonreflex tests detect analgesic action in rodents at clinically relevant concentrations.
        Ann NY Acad Sci. 2011; 1245: 11-13
        • Andrews N
        • Legg E
        • Lisak D
        • et al.
        Spontaneous burrowing behaviour in the rat is reduced by peripheral nerve injury or inflammation associated pain.
        Eur J Pain. 2012; 16: 485-495
        • Baron R
        • Binder A
        • Wasner G
        Neuropathic pain: diagnosis, pathophysiological mechanisms, and treatment.
        Lancet Neurol. 2010; 9: 807-819
        • Bennett G
        What is spontaneous pain and who has it?.
        J Pain. 2012; 13: 921-929
        • Bishop T
        • Hewson D
        • Yip P
        • et al.
        Characterisation of ultraviolet‐B‐induced inflammation as a model of hyperalgesia in the rat.
        Pain. 2007; 131: 70-82
        • Bishop T
        • Marchand F
        • Young A
        • et al.
        Ultraviolet‐B‐induced mechanical hyperalgesia: a role for peripheral sensitisation.
        Pain. 2010; 150: 141-152
        • Clemens L
        • Jansson E
        • Portal E
        • et al.
        A behavioral comparison of the common laboratory rat strains Lister Hooded, Lewis, Fischer 344 and Wistar in an automated homecage system.
        Genes Brain Behav. 2014; 13: 305-321
        • Cobos E
        • Portillo‐Salido E
        “Bedside‐to‐bench” behavioral outcomes in animal models of pain: beyond the evaluation of reflexes.
        Curr Neuropharmacol. 2013; 11: 560-591
        • Davies E
        • Boyle Y
        • Chizh B
        • et al.
        Ultraviolet B‐induced inflammation in the rat: a model of secondary hyperalgesia?.
        Pain. 2011; 152: 2844-2851
        • Deacon R
        Burrowing in rodents: a sensitive method for detecting behavioral dysfunction.
        Nat Protoc. 2006; 1: 118-121
        • Deacon R
        Burrowing: a sensitive behavioural assay, tested in five species of laboratory rodents.
        Behav Brain Res. 2009; 200: 128-133
        • Deacon R
        • Reisel D
        • Perry V
        • et al.
        Hippocampal scrapie infection impairs operant DRL performance in mice.
        Behav Brain Res. 2005; 157: 99-105
        • Gilron I
        • Jensen T
        • Dickenson A
        Combination pharmacotherapy for management of chronic pain: from bench to bedside.
        Lancet Neurol. 2013; 12: 1084-1095
        • Gustorff B
        • Anzenhofer S
        • Sycha T
        • et al.
        The sunburn pain model: the stability of primary and secondary hyperalgesia over 10 hours in a crossover setting.
        Anesth Analg. 2004; 98: 173-177
        • Gustorff B
        • Sycha T
        • Lieba‐Samal D
        • et al.
        The pattern and time course of somatosensory changes in the human UVB sunburn model reveal the presence of peripheral and central sensitization.
        Pain. 2013; 154: 586-597
        • Jirkof P
        Burrowing and nest building behavior as indicators of well‐being in mice.
        J Neurosci Methods. 2014; 234: 139-146
        • Mogil J
        Animal models of pain: progress and challenges.
        Nat Rev Neurosci. 2009; 10: 283-294
        • Mørch C
        • Gazerani P
        • Nielsen TA
        • et al.
        The UVB cutaneous inflammatory pain model: a reproducibility study in healthy volunteers.
        Int J Physiol Pathophysiol Pharmacol. 2013; 5: 203-215
        • O'Neill J
        • Sikander S
        • McMahon SB
        • et al.
        Translational studies of pain: Electrohpysiological validation of UVB induced sensitisation in rodents and QST profiling of healthy human volunteers.
        Society for Neuroscience Abstract Viewer and Itinerary Planner. 2013; 43
        • Rice AS
        • Cimino‐Brown D
        • Eisenach JC
        • et al.
        Animal models and the prediction of efficacy in clinical trials of analgesic drugs: a critical appraisal and call for uniform reporting standards.
        Pain. 2008; 15: 243-247
        • Rukwied R
        • Weinkauf B
        • Main M
        • et al.
        Inflammation meets sensitization – an explanation for spontaneous nociceptor activity?.
        Pain. 2013; 154: 2707-2714
        • Rutten K
        • Schiene K
        • Robens A
        • et al.
        Burrowing as a non‐reflex behavioural readout for analgesic action in a rat model of sub‐chronic knee joint inflammation.
        Eur J Pain. 2014; 18: 204-212
        • Rutten K
        • Robens A
        • Read SJ
        • et al.
        Pharmacological validation of a refined burrowing paradigm for prediction of analgesic efficacy in a rat model of sub‐chronic knee joint inflammation.
        Eur J Pain. 2014; 18: 213-222
        • Tallett AJ
        • Blundell JE
        • Rodgers RJ
        Night and day: diurnal differences in the behavioural satiety sequence in male rats.
        Physiol Behav. 2009; 97: 125-130
        • Weerasinghe NS
        • Lumb BM
        • Apps R
        • et al.
        Objective validation of central sensitization in the rat UVB and heat rekindling model.
        Eur J Pain. 2014; 8: 1199-1206
        • Yassen A
        • Passier P
        • Furuichi Y
        • et al.
        Translational PK‐PD modeling in pain.
        J Pharmacokinet Pharmacodyn. 2013; 40: 401-418
        • Zimmermann M
        Ethical guidelines for investigations of experimental pain in conscious animals.
        Pain. 1983; 16: 109-110