Ultrastructure of the Vesicular Component in the Intramural Nervous System of the Guiena-Pig’s intestines

Abstract

A systematic study of the vesicular component in the unmyelinated nerve fibers of the intestinal nervous plexus from the serosa to the mucosa of the guinea pig was made. This vesicular component containing dense granules with diameters from 300 to 1100 A was distinguished from the syaaptic vesicles of 100 to 500 A. Results from a study of the distribution of granules and vesicles of the myenteric plexus of the duodenum and colon and extraganglion nervous fibers of the mucosa, submucosa and muscularis suggest that the vesicles can be the site of synthesis and storage of substance P and 5-hydroxytryptamine.