Amines and peptides exert a wide range of physiological actions on both central neurons and peripheral tissues. Among these actions, serotonin and octopamine are known to trigger contrasting postures when injected into freely moving lobsters. Immunocytochemical studies of lobster ganglia have identified presumptive serotonergic neurons, their central and peripheral projections, and their termin...

Enterochromaffin cells in the duodenal mucosa were stained by using a monoclonal antibody against serotonin immunoreactive sites and an indirect immunoperoxidase technique. A semi-automatic image analysing system showed increased numbers of these cells in patients with untreated coeliac disease compared with a control group. The number of serotonin positive granules in individual enterochromaff...

Serotonin, a release product of activated platelets, stimulates proliferation and prostaglandin synthesis in cultured smooth muscle-like glomerular rat mesangial cells by activation of phospholipase and protein kinase C. To further characterize the signaling mechanisms used by serotonin, we monitored its effects on intracellular free Ca2+, pH, and membrane potential of cultured rat mesangial ce...

A series of photolabile o-nitrobenzyl derivatives of serotonin (caged serotonin) were synthesized: the amine-linked serotonin derivatives N-(2-nitrobenzyl) serotonin (Bz-5HT) and N-(alpha-carboxy-2-nitrobenzyl) serotonin (N-CNB-5HT), and O-alpha-carboxy-2-nitrobenzyl) serotonin (O-CNB-5HT), which has the caging group attached to the phenolic OH group. All the derivatives released free serotonin...

Although the enterochromaffin (EC) cell is one of the primary neuroendocrine regulatory cells of the small intestine, the lack of a purified cell system has precluded characterization of the cell and limited precise physiological evaluation. We developed methodology to obtain a pure population of Mastomys ileal EC cells, evaluated their functional regulation, and defined the transcriptome. Mast...

BACKGROUND The directed migration of neurons during development requires attractive and repulsive cues that control the direction of migration as well as permissive cues that potentiate cell motility and responsiveness to guidance molecules. RESULTS Here, we show that the neurotransmitter serotonin functions as a permissive signal for embryonic and postembryonic neuronal migration in the nema...

The presence of biogenic amines in cultured cells of mouse neuroblastoma C-1300 (clone NB-2a) was suggested by fluorescence-microscope histochemistry. Incubation in media containing L-[(14)C]tyrosine and L-[(14)C]tryptophan for 24 h, followed by high-voltage electrophoresis, radiochromatogram scanning, and scintillation counting, confirmed the presence of [(14)C]dopamine, [(14)C]norepinephrine,...

the regulation of dopamine and serotonin synthesis in rat brain striatal synaptosomes has been studied using hplc methods. noradrenaline was shown to markedly inhibit both the synthesis of dopamine and serotonin. the response of the synaptosomes to the concentrations of noradrenaline appeared to be biphasic, a very effective inhibition occurring at low concentrations (1-5 µm) and a relatively i...