[Confirmation of the presence of adrenergic fibers in human umbilical cord by electron microscopy].

1) In order to visualize biogenic catecholamine, the FAGLUPAGAS method, a new modification of the glyoxylic acid method, was used. Catecholaminergic fibers were observed chiefly in the intraarterial and surrounding region of arteries within Wharton's jelly. Periarterial plexus formation was also observed only in part of the umbilical cord near the umbilical ring. 2) Because first of all we had succeeded in detecting longitudinally running catecholaminergic fibers forming a periarterial plexus, we were able to prepare ultrathin sections exactly parallel to such fibers, and succeeded in confirming the presence of adrenergic fibers in human umbilical cord by electron microscopy.