The effect of transmural field stimulation on the serotonin content in rat duodenal enterochromaffin cells-in vitro

Abstract
The effect of transmural field stimulation (TFS)-in vitro-on the serotonin content in enterochromaffin cells (EC) in rat duodenum was studied by cytofluorimetry. TFS caused a significant 25% decrease of 5-HT in EC. The presence of tetrodotoxin or dl-propranolol in the stimulation bath antagonized the effect of TFS. In biopsies from rats pretreated with 6-OH-dopamine TFS had no effect on the 5-HT content in EC. The TFS induced decrease in 5-HT content may be due to a direct neural, probably .beta.-adrenoceptor mediated, influence on the EC.