CORRELATIVE EVIDENCE OF HYPERTENSION AND ALTERED COCHLEAR MICROHOMEOSTASIS - ELECTROPHYSIOLOGICAL CHANGES IN THE SPONTANEOUSLY HYPERTENSIVERAT

The spontaneously hypertensive rat model has been used to show that hy pertension is an important pathophysiological risk factor in age-relat ed hearing loss. In the present study, compound action potential (CAP) , electrochemical potential (ECP), and potassium concentration (C-K(+) ) measurements were taken from the cochlea of genetically predisposed, spontaneously hypertensive rats (SHR) and from normotensive Wistar-Ky oto (WKY) rats. In the SHR model, as the duration of hypertension incr eased with the animal's age (from 3 to 8 months), CAP thresholds incre ased, ECP increased in marginal cells only, and C-K(+) increased in bo th endolymph and marginal cells. Collectively, the data suggest that i onic alternations of cellular potentials are involved in hearing chang es in the hypertensive state. Ultimately, such data may assist in unde rstanding hearing loss in individuals who are diagnosed with hypertens ion.