Autonomic nervous regeneration in acetic acid‐induced ulcer from the viewpoint of synapse formation – effect of basic fibroblast growth factor and sofalcone in the rat

Summary Background: Monoclonal antibodies against GAP43 and synaptophysin, markers of regenerated nerves, have recently become available. Aim: To investigate the regeneration of the autonomic nerves after acetic acid treatment, as well as the effect of recombinant basic fibroblast growth factor (bFGF‐CS23) and sofalcone on reinnervation. Methods: Ulcers were induced by the direct application of 100% acetic acid to the serosal surface of the rat fundic stomach. Some rats were treated with bFGF‐CS23 or sofalcone every 12 h after the acetic acid treatment. The immunohistochemical location of GAP43 and synaptophysin was observed by confocal laser microscopy, and the uptake sites of 14C‐sofalcone were observed by autoradiography. Results: Both GAP43 and synaptophysin immuno‐reactivities surrounding microvessels were weak in the control group, whereas in the acetic acid‐treated group, these immunoreactivities were increased. Treatment with bFGF‐CS23 and sofalcone increased these immunoreactivities. The binding sites of sofalcone coincided with the location of regenerated nerves and surface mucous cells. The progenitors of the autonomic nerves were more abundant than expected. Conclusion: Both bFGF and sofalcone seem to stimulate nerve regeneration.