In Vivo Vestibular Blood Flow in the Mongolian Gerbil: Angiotensin Ill-provoked Changes in Systemic and Local Factors

Abstract

The current literature contains little information on vestibular end organ blood flow. The absence of an accepted model, difficulties applying dynamic in vivo measurement techniques and the inaccessibility of the inner ear organs contribute to the shortage of experimental findings. The purpose of the current study is to introduce the gerbil as a viable model for the in vivo study of vestibular blood flow dynamics. The potent vasoactive peptide, angiotensin III (AIII), was used to provoke blood pressure and blood flow changes. The results of this study demonstrate that viable blood flow measures may be obtained from the vestibule of the gerbil. Dose-dependent changes in blood pressure and vestibular blood flow were observed in response to high concentrations of AIII. Pretreatment with the receptor antagonist, sarthran, attenuated both blood pressure and blood flow increases in response to subsequent AIII infusions. The gerbil model offers the advanlages of easily accessible and identifiable peripheral vestibular organs, as well as responsive local blood flow. Investigations using this model may provide information on the regulation of blood flow during presentation with a variety of stimulus modalities. Information from such studies may lead to development of strategies for treatment of vestibulopathies suspected to be of vascular origins.

Key Words:

• angiotensin III
• gerbils
• vestibular blood flow