Candidate chemosensory cells in the porcine stomach.

A continuous chemosensory monitoring of the ingested food is of vital importance for adjusting digestive processes according to diet composition. Although any dysfunction of this surveillance system may be the cause of severe gastrointestinal disorders, information about the cellular and molecular basis of chemosensation in the gastrointestinal tract is limited. The porcine alimentary canal is considered as an appropriate model for the human gastrointestinal tract. Therefore, in this study we have investigated the gastric mucosa of swine for cells which express gustatory transduction elements such as TRPM5 or PLCβ2, and thus may represent candidate "chemosensors". It was found that the porcine stomach indeed contains cells expressing gustatory marker molecules; however, the morphology and topographic distribution of putative chemosensory cells varied significantly from that in mice. Whereas in the murine stomach these cells were clustered at a distinct region near the gastric entrance, no such compact cell cluster was found in the pig stomach. These results indicate substantial differences regarding the phenotype of candidate chemosensory cells of mice and swine and underline the importance of choosing the most suitable model organisms.