[Changes in vestibular function and furosemide test after experimental endolymphatic hydrops in guinea pigs].

The present study reports a successful anial model of endolymphatic hydrops (EH) in guinea pigs (n = 48) through a surgical obliteration of the endolymphatic sac and duct. Electronystagmography was calibrated by optokinetic nystagmus. During the formation of EH the vestibular functions (n = 16) were dynamically observed by ratation test. After eight weeks (n = 25) the furosemide tests with different doses were carried out by sinusoidal angular acceleration test. The results showed that the excitability of vestibular function in the operated ears was enhanced for the first week after operation, and then declined. At the eighth week it was significantly improved after intravenous injection of furosemide at the clinical equivalent dose level (1.25 mg/kg). The present results strongly support the usefulness of furosemide test in the diagnosis of EH. The possible mechanisms of its effect are discussed.