Comparative quantitative estimation of the granular vesicles in the intramural ganglia of Auerbach's plexus in the nonsphincter and sphincter parts of cat alimentary tract.

The spatial size and density of the granular vesicles (GV) in the axonal varicosities of the intramural ganglia in parts of the alimentary tract adjacent to the lower esophageal, pyloric and ileo-caecal sphincters are determined. The results obtained are compared with the data about the density and size of GV in these sphincters, described earlier (Lolova et al., 1980). The results concerning GV size show: (1) absence of very small differences in GV diameters from the 1st and 2nd populations (average diameter around 40, respectively 55 nm) between the sphincter and nonsphincter parts; (2) absence of 3rd population GV (average diameter 77 and 90 nm) in the nonsphincter parts of the fundus close to the terminal ileum; (3) GV from 4th and 5th populations (average diameter around 125 nm, 150 nm respectively) are larger in the nonsphincter parts than in the sphincters. The following observations are made with respect to GV density: (1) the smallest GV have the greatest density in all parts studied; (2) the GV density from the different populations differs in the nonsphincter and sphincter parts; (3) certain characteristic features become prominent upon comparing GV density in the parts of the gastro-intestinal tract from cranial to distal direction. The results obtained are discussed with a view to the functional characteristics of the nonsphincter and sphincter parts and with the participation of various transmitters in them.