The relationship between gastrin cells and bombesin-like immunoreactive nerve fibres in the gastric antral mucosa of guinea-pig, rat, dog and man.

The relationship between bombesin-like immunoreactive (bombesin-LI) nerve fibres and gastrin-LI G-cells was examined in gastric antral mucosa from guinea-pig, rat, dog and man using a double-labelling fluorescence immunohistochemical technique. The greatest density of bombesin-LI nerve fibres was found within the basal mucosa in all species and the density of innervation decreased towards the luminal surface. Most G-cells were in a band occupying approximately the middle third of the mucosa. The proportion of G-cells found within a distance of 2 microns from bombesin-LI nerve fibres was low in all species (6% in the guinea-pig, 22% in the rat, 14% in the dog, and 9% in the human). It is proposed that the neuropeptide released from bombesin-LI antral mucosal nerve fibres traverses distances of greater than several microns to reach the target G-cells. This may be achieved by passage through the mucosal microcirculation.