Choline acetyltransferase (ChAT) immunoreactivity in a sub-population of mammalian intestinal endocrine cells

1. The distribution of choline acetyltransferase (ChAT) in rat and guinea-pig intestine has been analysed using an indirect immunofluorescence technique. 2. ChAT immunoreactivity was apparent in nerve fibres and cell bodies of the myenteric and submucous plexus and in fibres throughout the muscle coats and the mucosa. 3. Staining was also evident in a sub-population of mucosal endocrine cells in the small intestine, implying the existence of this enzyme and its product (acetylcholine) in these cells. 4. These data are consistent with previous observations on the distribution of ChAT activity in mammalian intestine.