[Effect of nitric oxide in vestibular compensation].

Objective: To study the effect of nitric oxide (NO) in vestibular compensation after unilateral vestibular deafferentation.

Methods: Eighteen animals were divided into two groups, 6 of group a as control, 12 of group b received gentamicin intratympanic injection in the left ear. Half of the animals were killed respectively after 5 days and 10 days. Vestibular endorgan and brainstem tissue sections were subjected to NADPH-d reactive test of NOS for histochemical examination.

Results: In group a, NOS-like reactivity in both sides of vestibular endorgan and nucli. In group b during 5 days, NOS-like reactivity in right side of vestibular endorgan and nucli, those of the left side were negative. During 10 days, NOS-like reactivity only in the right side of vestibular endorgan.

Conclusions: Changes of NOS expression in the contralateral vestibular nucli might have played a role in vestibular compensation.