Metabolic origins of 5-hydroxytryptamine in enteric neurons in a teleostean fish (Platycephalus bassensis), a toad (Bufo marinus) and the guinea-pig.
1. 5-Hydroxytryptamine (5-HT) content and synthesis in mucosa-free intestine of guinea-pig, the teleost Platycephalus bassensis and the amphibian Bufo marinus was studied by HPLC with electrochemical detection or by TLC. 2. The 5-HT content of small intestine was: guinea-pig 0.58; Bufo: 1.23; Platycephalus: 26.88 nmol/g. 3. Intestine from each species synthesized 5-HT from exogenous 5-HTP. 4. Platycephalus preparations synthesized labelled 5-HT from 14C-tryptophan, but no labelled 5-HT was detected after similar incubation of guinea-pig or Bufo preparations. 5. Incubation of guinea-pig preparations with tryptophan did not increase tissue 5-HT or 5-HIAA content. 6. 5-HT in Platycephalus enteric neurons may be synthesized from tryptophan in situ; 5-HT in Bufo and guinea-pig neurons may be synthesized elsewhere, perhaps in enterochromaffin cells.
Anderson
C R
CR
Department of Zoology, University of Melbourne, Parkville, Victoria, Australia.
Campbell
G
G
Payne
M
M
D000818:Animals; D002024:Bufo marinus / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004563:Electrochemistry; D005399:Fishes / Q000378:metabolism*; D006168:Guinea Pigs; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid