PCR detects bands consistent with the expression of receptors associated with pruritus in canine dorsal root ganglia.

Abstract

BACKGROUND: Various mediators are involved in the induction of itch, i.e. pruritus; however, the in vivo pharmacology of pruritus seems to be different in distinct species, and little is known about receptors that are involved in the induction of itch in dogs. The species differences in the mediation of pruritus might be explained by species differences in receptor expression in the sensory nerves, including the dorsal root ganglia (DRG). HYPOTHESIS/OBJECTIVES: The aim of the study was to analyse the expression of receptors for various mediators of pruritus in canine DRG. METHODS: Dorsal root ganglia of 14 dogs, which were euthanized for reasons not related to this study, were analysed. Multiple DRG per dog were dissected and, after homogenization of the DRG tissues, total RNA was isolated, reverse transcribed to complementary DNA and amplified with custom-synthesized primers. RESULTS: The following receptors were found in canine DRG: transient receptor potential cation channel subfamily V member 1, tachykinin receptor 1, Toll-like receptor 7, endothelin receptor type A, opioid receptors μ1 and κ1, histamine H1 -H4 receptors and the interleukin-31 receptor complex. CONCLUSIONS AND CLINICAL IMPORTANCE: PCR analysis detected bands consistent with the expression of receptors associated with pruritus in canine DRG.