title: Influence of glucocorticoids on a time-of-day-dependent variation in intradermal reactivity to histamine in dogs.
abstract: The objectives of this study were to determine daily variation in intradermal reactivity to histamine in dogs and to evaluate a potential influence of glucocorticoids on reactivity. Wheal sizes formed after intradermal injections of histamine were measured every 6 h during a single 24 h period in six healthy dogs. To determine whether glucocorticoids were implicated in daily variation, intradermal reactivity to histamine was evaluated at 9:00 h and at 21:00 h during a single day in dogs that received oral prednisolone (a synthetic glucocorticoid) or oral trilostane (an inhibitor of endogenous glucocorticoid synthesis). Finally, the time required for the histamine reaction to diminish after an intravenous injection of hydrocortisone was also assessed. A significant time-of-day-dependent variation in intradermal reactivity to histamine was detected in dogs, with a larger wheal size observed at 9:00 h than at 21:00 h. Administration of prednisolone or trilostane disrupted this variation. Intradermal reactivity to histamine was significantly reduced 6 h after an intravenous injection of hydrocortisone. These results suggest that glucocorticoid secretion from the adrenal glands could be involved in the regulation of daily variation in histamine-mediated reactions in dogs.
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Goto
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Sunao
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Miwa
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Hironari
authors.initials: H
authors.lastname: Osada
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Shimoda
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nagai
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Junsuke
authors.initials: J
authors.lastname: Shirai
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Itoh
authors.affiliation: Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan. Electronic address: k-ohmori@cc.tuat.ac.jp.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Ohmori
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D002940:Circadian Rhythm; D013196:Dihydrotestosterone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004285:Dogs; D005938:Glucocorticoids / Q000008:administration & dosage*; D006632:Histamine / Q000276:immunology*; D017442:Histamine Agonists / Q000276:immunology*; D006854:Hydrocortisone / Q000008:administration & dosage*; D007271:Injections, Intradermal / Q000662:veterinary; D007275:Injections, Intravenous / Q000662:veterinary; D008297:Male; D011239:Prednisolone / Q000008:administration & dosage*; D013997:Time Factors
chemical_list: D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D017442:Histamine Agonists; D013196:Dihydrotestosterone; D006632:Histamine; D011239:Prednisolone; C009954:trilostane; D006854:Hydrocortisone
keywords: Canine; Circadian rhythm; Cutaneous reactions; Glucocorticoids; Histamine