title: The occurrence and distribution of 5-hydroxytryptamine in Hymenolepis diminuta and H. nana.
abstract: The presence of 5-HT in Hymenolepis diminuta and Hymenolepis nana was detected by 2 biochemical methods and as yellow fluorescence in a histochemical method. In H. diminuta, 5-HT was found in a concentration of about 1.2 micron/g; this amount did not vary significantly in worms aged 6 to 18 days or more or in various regions of the worm. In H. nana, 5-HT was found in a concentration of about 1.8 micron/g. It was histochemically localized in H. diminuta and H. nana in a pattern similar to that of acetylcholinesterase previously described in these 2 cestodes, and it may be the opposing neuro-transmitter to acetylcholine. The lack of 5-HT in the vestigial rostellum of H. diminuta may be correlated with loss of function of this organ.
mesh_terms: D000818:Animals; D002589:Cestoda / Q000032:analysis*; D006651:Histocytochemistry; D006926:Hymenolepis / Q000032:analysis* / Q000033:anatomy & histology; D008856:Microscopy, Fluorescence; D012701:Serotonin / Q000032:analysis*
chemical_list: D012701:Serotonin