title: Nitric oxide donors as treatment for grass induced acute laminitis in ponies.
abstract: The potential for participation of the arginine-nitric oxide system in the aetiology of acute equine laminitis has been assessed. Nitric oxide (NO), produced by the action of NO synthase (NOS) on its substrate l-arginine, relaxes vascular smooth muscle to cause vasodilation. An attenuated normal vasodilatory tone may characterise the pathogenesis of acute equine laminitis. An intravenous infusion of 10% l-arginine in 0.9% saline caused vasodilatation in the hoof of a normal pony and immediate reperfusion of laminal tissues in an acutely laminitic pony, detected noninvasively by near infrared spectroscopy (NIRS), but the amino acid had little effect on systemic blood pressure. Treatment of acute laminitis with glyceryl trinitrate applied topically to the pasterns reduced the typical 'bounding pulses' in treated limbs, reduced lameness and lowered systemic blood pressure. Nitric oxide is likely to participate in the multifactorial pathogenesis of equine laminitis.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, UK.
authors.forename: K A
authors.initials: KA
authors.lastname: Hinckley
authors.forename: S
authors.initials: S
authors.lastname: Fearn
authors.forename: B R
authors.initials: BR
authors.lastname: Howard
authors.forename: I W
authors.initials: IW
authors.lastname: Henderson
mesh_terms: D000208:Acute Disease; D000279:Administration, Cutaneous; D000818:Animals; D001120:Arginine / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D002319:Cardiovascular System / Q000187:drug effects; D005534:Foot Diseases / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006724:Hoof and Claw; D006734:Horse Diseases / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D006736:Horses; D007275:Injections, Intravenous; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology / Q000627:therapeutic use*; D019001:Nitric Oxide Synthase / Q000502:physiology; D005996:Nitroglycerin / Q000008:administration & dosage / Q000627:therapeutic use; D006109:Poaceae; D013053:Spectrophotometry; D014664:Vasodilation / Q000502:physiology; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D014665:Vasodilator Agents; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D005996:Nitroglycerin