Effects of acute and chronic hypertension on the labyrinthine barriers in rat

• Published in: Hearing research 2001, Vol.151 (1-2), p.227-236
• Main Authors: MOSNIER, Isabelle, TEIXEIRA, Marie, LOISEAU, Alain, FERNANDES, Isabelle, STERKERS, Olivier, AMIEL, Claude, FERRARY, Evelyne
• Format: Article
• Language: English
• Subjects: Acute Disease; Animals; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Chronic Disease; Cochlea - physiopathology; Ear, Inner - physiopathology; Endolymph - physiology; Experimental diseases; Hypertension - physiopathology; Male; Mannitol - cerebrospinal fluid; Mannitol - pharmacokinetics; Medical sciences; Membrane Potentials; Perilymph - physiology; Permeability; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Urea - cerebrospinal fluid; Urea - pharmacokinetics
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/S0378-5955(00)00229-X

Hearing loss, vertigo, and tinnitus have been related to arterial hypertension. The aim of the present work was to study the permeability of the blood-perilymph and of the labyrinthine barrier, between endolymph and perilymph, to small molecules during chronic and acute hypertension. Experiments were performed in normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Acute hypertension was induced by phenylephrine. Perilymph was sampled from the first turn of the scala vestibuli and the Na, K, urea, and radioactive concentrations ((14)C-urea and (3)H-mannitol) were measured. In another experimental set, the endocochlear potential was recorded from the basal turn of scala media, before and after phenylephrine injection. The composition of the perilymph and the kinetic constants for (14)C-urea and (3)H-mannitol were similar in WKY and SHR, and not modified after acute hypertension. In endolymph, the endocochlear potential in SHR (+80+/-2.7 mV, n=24) was lower (P