[Glycerol opening of blood-labyrinth barrier using electron-opaque tracer ferritin]

Fifteen guinea pigs were divided into three groups: the control, the ferritin and the glycerol-ferritin groups. In the first group, no any medication had been given; in the second group, ferritin 1 gm/kg was injected via the jugular vein; in the third group, 50% glycerol 3 ml/kg was injected 30, 60 and 120 minutes prior to the injection of ferritin. Striae were removed, fixed and embedded in Epon. Ultra-thin sections were cut and observed under electron microscope. No ferritin molecule was seen in the control group. In the ferritin group, the ferritin particles were seen in stria capillary only. In the glycerol-ferritin group, the ferritin molecules had entered the endothelial cells of stria capillary at 30 minutes. Ferritin molecules had got into stria vascularis and accumulated around the mitochondria at 60 minutes. The electron-opaque tracers had migrated to the apex of the marginal cells along microtubular system and permeated to the endolymphatic space through cell membranes and junctions. The ferritin particles appeared at the surface of marginal cells in the endolymphatic space at 120 minutes. The results indicate that glycerol can serve as an opener of blood-labyrinth barrier.