[Effects of induced hyperemia on the concentration of a labeled substance in the internal ear]

Cochlear neuroepithelial cells contain a lot of mitochondria which is an indication of a high rate of metabolism in the organ. However, blood flow in the internal ear is low because vessels of the stria vascularis have no muscular layer or vasomotor innervation. Therefore in case of a disease reactive hyperemia which may lead to the restoration of blood supply should not be expected. Internal ear circulation may be influenced by compressing internal jugular veins to produce venous hypertension and hyperemia. Rabbit experiments in which internal jugular veins were ligated showed that the concentration of a labeled substance in the ear preparation increased by 72.8% within an hour after intravenous injection as compared to the controls. This effect is due to an increase of transcapillary filtration and transmural permeability in the terminal circulation area. However, venous hyperemia has certain disadvantages which makes it necessary to develop better approaches to blood from control as a method of therapy of internal ear diseases.