Ultrastructure of elastic fibers as shown by polarization optics after the topo-optical permanganate-bisulfite-toluidine blue (PBT) reaction.

Permanganate-bisulfite-toluidine blue (PBT) reaction proved to be a highly selective and sensitive method for demonstration of elastic structures in tissue sections. Permanganate oxidation liberates a great amount of aldehyde groups in young and adult elastic fibers both in bovine ligamentum nuchae which can be demonstrated with the bisulfite-toluidine blue (pH = 1.0) staining procedure. There are suggestive evidences that the aldehyde groups are liberated from the desmosine and isodesmosine cross bondings of elastin. The dichroism and the strong birefringence of the elastic fibers induced by the PBT reaction indicate a high degree of linear fibrillar molecular order of the reacting elastin molecules which are assumed to be arranged helically in the aortic elastic fibers and they are assumed to show 2 different micellar textures in ligamentum nuchae fibers as reported with other topo-optical reactions earlier by Romhanyi.