Effect of lateral hypothalamic area lesions on serotonin-containing epithelial cells in rat duodenum

The aphagic effect of lateral hypothalamic area (LHA) lesions induced by kainic acid injection on serotonin (5HT)-containing epithelial cells in rat duodenum was studied in comparison with food deprived rats. The densities of 5HT cells were evaluated by quantitative morphometry using fluorescent histochemical longitudinal sections. The levels of 5HT/mg tissue were determined by HPLC on acid extracts of isolated villous epithelium. Body and duodenal weight losses, as well as duodenal mucosal atrophy, were comparable in the two groups of starved animals, i.e., one is food deprived and the other is lesioned animals. The numbers of 5HT cells in these starved groups were similar to those in controls so that the densities were increased. The 5HT/mg tissue in food-deprived animals was similar to that in controls but significantly higher in the LHA-lesioned group. These results are interpreted in terms of a possible central regulatory mechanism that is intact in the food-deprived animals but destroyed in the lesioned animals.