[Ultramicroscopic study of the mucosa of the lower 3d of the ureter]

A study has been made, using an electronic microscope, of the mucosa of the lower third of the ureter of rats, including a description of three kinds of cells with their own ultrastructural characteristics. One may emphasize the presence of intraepithelial nerve endings and chromaffin type granular formations. In some cells, adjacent to the basal membrane, there is also a perinuclear structure described, consisting of tonofilaments (perinuclear crown of tonofilaments) which it is thought could affect the genesis of distension stimuli.