Ultrastructural demonstration of exocytosis in the intact rat adrenal medulla

J Electron Microsc Tech. 1989 Aug;12(4):316-22. doi: 10.1002/jemt.1060120404.


Evidence is presented for morphological proof of exocytosis in the rat adrenal medulla in situ. Techniques were modified to allow perfusion of the intact adrenal gland with secretagogues (or electrical stimulation) followed by tannic acid. Unstimulated specimens demonstrated exocytotic (omega-shaped) profiles filled with flocculent material. This flocculation was also seen in the intercellular space. Stimulation of the adrenal medulla also resulted in the appearance of exocytotic profiles and an accumulation of the flocculent mass. This was often most evident in the subendothelial space. This is the first demonstration of exocytosis in the rat adrenal medulla by electron microscopy. The techniques used in this study will be useful for studying the pathway of secretory products of the adrenal chromaffin cell before they enter the vascular system.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adrenal Medulla / metabolism
  • Adrenal Medulla / ultrastructure*
  • Animals
  • Electric Stimulation
  • Exocytosis*
  • Extracellular Space / metabolism
  • Extracellular Space / ultrastructure
  • Hydrolyzable Tannins
  • Perfusion
  • Rats
  • Vasoactive Intestinal Peptide / metabolism


  • Hydrolyzable Tannins
  • Vasoactive Intestinal Peptide