Abstract
To investigate whether induction of the ultraviolet B and heat rekindling (UVB/HR) model alters burrowing behaviour in rats.
Study designRandomized, blinded, prospective experimental study.
AnimalsSixteen adult male Wistar rats weighing 250–300 g.
MethodsIn 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.
ResultsRats 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 relevancePain 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.
Original language | English |
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Pages (from-to) | 579–585 |
Number of pages | 7 |
Journal | Veterinary Anaesthesia and Analgesia |
Volume | 43 |
Issue number | 5 |
Early online date | 12 Feb 2016 |
DOIs | |
Publication status | Published - Sept 2016 |
Keywords
- burrowing
- heat rekindling
- pain
- rat
- ultraviolet B