Studies of Cochlear Blood Flow in Guinea Pigs with Endolymphatic Hydrops

• Published in: O.R.L. Journal for oto-rhino-laryngology and its related specialties Vol. 60; no. 1; pp. 4 - 11
• Main Authors: Yazawa, Yoshiro, Kitano, Hiroya, Suzuki, Mikio, Tanaka, Hirosi, Kitajima, Kazutomo
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Karger 01.01.1998; S. Karger AG
• Subjects: Animals; Atrophy - pathology; Biological and medical sciences; Cochlea - blood supply; Cochlea - pathology; Endolymphatic Hydrops - pathology; Endolymphatic Sac - blood supply; Ent, orbit; Guinea Pigs; Investigative techniques, diagnostic techniques (general aspects); Laser-Doppler Flowmetry - methods; Medical sciences; Original Paper; Regional Blood Flow; Stria Vascularis - pathology; Time Factors; Ultrasonic investigative techniques; Laser Doppler flowmetry; Guinea pig; Isosorbide; Cochlear blood flow; Hyperosmotic solutions; Endolymphatic hydrops; Mannitol; Glycerol; Antiglaucomatous agent; Intravenous administration; Laxative; Diuretic; Infusion; Laser dopplerometry; ENT disease; Flowmetry; Sonography; Induction; Internal ear disease; Rodentia; Exploration; Experimental study; Blood flow; Diagnostic agent; Vertebrata; Mammalia; Animal; Osmotic diuretic; Cochlea; Meniere disease
• ISSN: 0301-1569; 1423-0275
• DOI: 10.1159/000027554

Laser Doppler flowmetry was used to assess cochlear blood flow (CoBF) in guinea pigs with experimental endolymphatic hydrops following intravenous infusion of 5 types of drugs: 50% glycerol, 70% isosorbide, 20% mannitol, 7% sodium bicarbonate, and 1% diphenidol. The magnitude of the CoBF changes following infusion tended to be smaller in the hydropic ears than in the normal control ears. A significant reduction in CoBF changes was observed in hydropic ears infused with isosorbide and sodium bicarbonate. These results suggest that the cochlear microvascular sensitivity to various stimuli such as drug infusion is reduced in hydropic ears. This may result from atrophy of the stria vascularis which is often observed in the hydropic ears of guinea pigs. Thus it seems likely that the same reaction occurs in the inner ear of patients with Ménière’s disease in whom atrophy of the stria vascularis is also presumed to exist in conjunction with extensive endolymphatic hydrops. Therefore, it seems probable that the function of the microvasculature of the stria vascularis is impaired in the inner ear of patients with Ménière’s disease, resulting in the slow progressive deterioration of the inner ear with time.