Dopamine has been implicated in the healing process within the gastrointestinal tract; however, no local source for the dopamine has been located. Last year we determined that the pancreas synthesizes dopamine and releases it into the duodenum. Using immunohistochemistry, in situ hybridization, histochemistry, Western blotting, RT-PCR, and radioactive uptake studies, we have also localized a source of dopamine in the gastric mucosa. This finding suggests that the stomach makes dopamine as a protective agent. We also determined that the most likely site of action is the dopamine D1b receptor, and suggest that a specific agonist to this receptor might prove useful in treating gastrointestinal mucosal injuries. We have also mapped the distribution of the five somatostatin receptors in the gastrointestinal tract. We have described the exclusive presence of the somatostatin receptor SST2A subtype in the pancreas islet glucagon-containing cells, suggesting the possible use of an SST2A agonist as a new class of antidiabetic drugs.
Hunyady, B; Palkovits, M; Mezey, E (2000) Vesicular monoamine transporters in the rat stomach. J Physiol Paris 94:123-30 |
Mezey, E; Eisenhofer, G; Hansson, S et al. (1999) Non-neuronal dopamine in the gastrointestinal system. Clin Exp Pharmacol Physiol Suppl 26:S14-22 |