thiourea and Skin-Diseases

Histamine is a well known mediator of allergic skin diseases and, with the discovery of the histamine H(4) receptor, the role of histamine is re-evaluated. There are only limited published data elucidating the role of the histamine H(4) receptor in dogs. Twelve beagles intradermally injected with histamine (0.25 micromol and 2.5 micromol/site) reacted with a classical wheal and flare reaction. None of the dogs showed signs of pruritus. The dogs reacted with a wheal and flare reaction after intradermal injection of histamine H(4) receptor agonist/H(3) receptor antagonist clobenpropit (0.1 micromol) and selective histamine H(4) receptor agonist VUF 8430 (1.5 micromol). Again, no scratching occurred in any of the dogs. The highly selective histamine H(4) receptor antagonist JNJ 7777120 reduced the histamine-induced wheal reaction in nine out of 12 dogs. To determine whether canine mast cells are susceptible to histamine H(4) receptor-mediated reactions, effects of clobenpropit and VUF 8430 were tested in canine mastocytoma cells (C2). Incubation with histamine H(4) receptor agonists (up to 10 micromol/L) induced a distinct calcium(2+) influx. C2 cells also responded with enhanced chemotaxis when stimulated with histamine, VUF 8430 and clobenpropit. Neither VUF 8430, nor clobenpropit (up to 10 micromol/L) led to a modulation of histamine concentration in supernatants of canine mastocytoma cells, whereas mastoparan, used as a positive control, enhanced histamine concentration in supernatants. For treatment of allergic skin diseases in dogs, a combination of H(1)R and H(4)R antagonists might be advantageous.

Topics: Animals; Calcium; Cell Line; Dog Diseases; Dogs; Dose-Response Relationship, Drug; Female; Guanidines; Histamine; Histamine Agonists; Histamine Antagonists; Imidazoles; Indoles; Inflammation; Intercellular Signaling Peptides and Proteins; Male; Mastocytoma; Mice; Mice, Inbred BALB C; Peptides; Piperazines; Receptors, G-Protein-Coupled; Receptors, Histamine; Skin Diseases; Thiourea; Wasp Venoms

Topics: Anti-Infective Agents, Local; Homeopathy; Humans; Philosophy, Medical; Placebo Effect; Professional Competence; Skin Diseases; Thiourea

Topics: Anti-Infective Agents, Local; Attitude of Health Personnel; Greece; Humans; Materia Medica; Professional Practice; Skin Diseases; Thiourea; United Kingdom

Topics: Acne Vulgaris; Adolescent; Adult; Copper; Dermatitis; Dermatitis, Contact; Diving; Female; Granuloma; Hair Color; Humans; Larva Migrans; Male; Mycobacterium Infections; Seaweed; Skin Diseases; Skin Ulcer; Swimming; Thiourea

Topics: Anti-Infective Agents, Local; Female; Formaldehyde; Humans; Hydroxyurea; Skin Diseases; Thiourea; Urea; Urinary Bladder Diseases; Vaginitis

Topics: Animals; Chemistry, Organic; Cornea; Guinea Pigs; Lidocaine; Male; Mice; Organic Chemistry Phenomena; Reflex; Skin Diseases; Thiourea