Expression of purinergic P2X receptor subtypes 1, 2, 3 and 7 in equine laminitis.
Tissue sensitisation and chronic pain have been described in chronic-active laminitis in the horse, making treatment of such cases difficult. Purinergic P2X receptors are linked to chronic pain and inflammation. The aim of this study was to examine the expression of purinergic P2X receptor subtypes 1, 2, 3 and 7 in the hoof, palmar digital vessels and nerve, dorsal root ganglia and spinal cord in horses with chronic-active laminitis (n=5) compared to non-laminitic horses (n=5). Immunohistochemical analysis was performed on tissue sections using antibodies against P2X receptor subtypes 1-3 and 7. In horses with laminitis, there was a reduction in the thickness of the tunica media layer of the palmar digital vein as a proportion of the whole vessel diameter (0.48±0.05) compared to the non-laminitic group (0.57±0.04; P=0.02). P2X receptor subtype 3 was expressed in the smooth muscle layer (tunica media) of the palmar digital artery of horses with laminitis, but was absent in horses without laminitis. There was strong expression of P2X receptor subtype 7 in the proliferating, partially keratinised, epidermal cells of the secondary epidermal lamellae in the hooves of horses with laminitis, but no immunopositivity in horses without laminitis.
Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Leahurst Campus, Chester High Road, Neston, Cheshire CH64 7TE, UK.
Danae E
DE
Zamboulis
Mark
M
Senior
Peter D
PD
Clegg
Peter I
PI
Milner
D000818:Animals; D005534:Foot Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D005786:Gene Expression Regulation; D006734:Horse Diseases / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006736:Horses; D007150:Immunohistochemistry / Q000662:veterinary; D009928:Organ Specificity; D058469:Receptors, Purinergic P2X / Q000235:genetics* / Q000378:metabolism
D058469:Receptors, Purinergic P2X
Equine; Immunohistochemistry; Laminitis; Purinergic P2X receptor