Variations of somatostatin-like immunoreactivity in the circumoesophageal ganglia, the hepatopancreas, the mantle edge, and the hemolymph of shell-repairing snails (Helix aspersa).

Immunocytology and radioimmunoassays demonstrate the presence of immunoreactive somatostatin-like (IR-SOM-LI) material in the tissues of young or adult snails Helix aspersa bred under short or long day in controlled artificial conditions. Neurosecretory cells in the circumoesophageal ganglia and in the digestive gland, small fibers in the hepatopancreas, and small granules in the mantle epithelial cells are immunoreactive toward antisomatostatin. In all experimented animals shell fractures induce variations of the IR-SOM-LI concentrations in all assayed tissues whatever the lighting conditions were underwent. These findings support the hypothesis that in Helix one or more substances related to the vertebrate tetradecapeptide is (are) involved in the repair processes but that the storage and the metabolism may be different during the biological cycle of the snails. These results are compared with those previously published using different gastropods and different methods.