title: Immobilization stress induces elevation of intraocular pressure in rabbits.
abstract: The aim of this study was to test whether immobilization and intravenous volume load as stressors influence the intraocular pressure in rabbits. Rabbits were immobilized for 1 h in a horizontally placed plastic tube with an internal diameter of 13.2 cm and a length of 33.2 cm. After immobilization, rabbits received rapid intravenous drip infusion of 5% glucose solution, 20 ml/kg of body weight, in 5 min. The intraocular pressure immediately after immobilization (11.2 +/- 3.0 mm Hg; mean and standard deviation) was significantly higher compared to control rabbits without immobilization (9.2 +/- 1.0 mm Hg, Student's t test, p = 0.0462). This difference became significantly larger when volume load was exerted on both groups of rabbits (22.7 +/- 5.6 versus 16.4 +/- 2.2 mm Hg, p = 0.0067). Serum levels of cortisol, adrenaline, and noradrenaline were significantly elevated after immobilization (p = 0.0002, p = 0.0271, p = 0.0296, respectively). Venous pressure of the ear tended to increase in rabbits immediately after immobilization (15.8 +/- 3.1 mm Hg) compared with control rabbits (8.5 +/- 2.3 mm Hg), and the difference became significant when volume load was exerted on both groups of rabbits (20.8 +/- 7.4 versus 9.2 +/- 4.8 mm Hg, p = 0.0211). In conclusion, we clearly demonstrated that physical stress due to immobilization, especially in combination with volume load, increased intraocular pressure in rabbits.
authors.affiliation: Department of Ophthalmology, Okayama University Medical School, Okayama City, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: T
authors.initials: T
authors.lastname: Matsuo
authors.forename: Y
authors.initials: Y
authors.lastname: Kurabayashi
mesh_terms: D000818:Animals; D001810:Blood Volume / Q000187:drug effects; D002940:Circadian Rhythm; D004837:Epinephrine / Q000097:blood; D005947:Glucose / Q000008:administration & dosage; D006854:Hydrocortisone / Q000097:blood; D007103:Immobilization / Q000009:adverse effects*; D007262:Infusions, Intravenous; D007429:Intraocular Pressure; D009638:Norepinephrine / Q000097:blood; D009798:Ocular Hypertension / Q000097:blood / Q000209:etiology*; D011817:Rabbits; D013312:Stress, Physiological / Q000097:blood / Q000150:complications*; D014065:Tonometry, Ocular; D014690:Venous Pressure
chemical_list: D005947:Glucose; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine