Ruthenium red staining material in Herbst and Grandry sensory corpuscles

The penetration and distribution of ruthenium red into Herbst and Grandry sensory corpuscles has been investigated. Ruthenium red positive substances have been localized in all intercellular spaces including the collagen fibrils, basement membranes and predominately the outer leaflet of the plasmalemmae including the axolemma. Some of the numerous pinocytotic and coated vesicles of the receptor cell layers have been heavily loaded with the dye. Sometimes, the intracytoplasmic and intraaxoplasmic penetration of ruthenium red has been observed. In these cases, the dye deposits have been restricted to the elements of smooth endoplasmic reticulum, mitochondria and microtubules.