Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P08908 (5-HT1A)
 5,574 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serotonin enhances acetylcholine-elicited contractions of buccal muscle E1 of Aplysia. To characterize the serotonin receptor, actions of ligands of specific serotonin receptor subtypes were examined. Ketanserin, an antagonist at 5-HT2 receptors, had little effect. Two 5-HT1A ligands, LY165163 and 8-OH-DPAT, mimicked the effect of serotonin, although with slower kinetics. This suggests that the peripheral serotonin receptor in Aplysia more closely resembles 5-HT1 than 5-HT2 receptors.
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PMID:LY165163 and 8-OH-DPAT have agonist effects on a serotonin responsive muscle of Aplysia. 295 1

Cholinergic and serotonergic receptors of Aplysia californica buccal muscles were characterized pharmacologically by determining compounds that effectively inhibited contractile responses to acetylcholine (ACh) and modulatory effects of serotonin (5-HT), respectively. pA50 for ACh to elicit contraction averaged 4.7 +/- 0.1 (mean +/- SE, equivalent to 2 x 10(-5) M). Both hexamethonium bromide and atropine inhibited ACh-elicited contractions, but neither inhibited the response completely, nor were the two together able to antagonize the response completely. Curare caused inhibition only at low ACh doses, and muscarinic antagonists pirenzapine and 4-diphenylacetoxy-N-methylpiperidine methiodide caused partial inhibition. The most effective blocker of ACh-elicited contractions was the nicotinic antagonist mecamylamine. 10(-4) M mecamylamine completely blocked the cholinergic response. ACh contractions were inhibited 90% within 10 min and took > 40 min to recover from mecamylamine. Specificity was indicated by the lack of effect of mecamylamine on potassium-elicited contraction. NAN-190 blocked the potentiating effect of 5-HT without having inhibitory or potentiating effects by itself on ACh-elicited contractions. NAN-190 blocked the potentiating effect of 8-OH-DPAT. Cholinergic receptors on Aplysia buccal muscles are most effectively inhibited by mecamylamine and may have mixed nicotinic/muscarinic character. Serotonergic receptors have pharmacological similarities to vertebrate 5-HT1A receptors and may be closely related to the gastropod 5-HTlym receptor.
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PMID:Antagonists of cholinergic and serotonergic responses of Aplysia buccal muscle. 774 91

Serotonin has been shown to be a neuromodulator in the Aplysia californica CNS. The diversity of serotonin actions is due to the existence of several different receptor subtypes. In this study we report the cloning of a full-length cDNA, coding for a novel serotonin receptor (5-HTap2). The receptor protein bears the characteristics of G protein-coupled receptors. It shares 68% and 34% of its amino acid sequence identity with the 5-HTlym receptor from Lymnaea stagnalis and the mammalian 5-HT1A receptor, respectively. When transfected in HEK 293 cells, 5-HTap2 was negatively coupled to adenylate cyclase. Ligand binding analysis indicated that the order of potencies of various drugs for the inhibition of [3H]LSD binding was: methiothepin > metergoline > 5-CT > PAPP > 5-HT > ketanserin > NAN-190 > 8-OH-DPAT > clozapine. RT-PCR amplification of RNA isolated from different tissues indicated that this receptor is expressed in the CNS and in bag cells. The expression of 5-HTap2 restricted to the CNS suggests an important role for this receptor in the modulation of neuronal functions in Aplysia. Moreover, the high expression of 5-HTap2 in the bag cells, associated with its pharmacological profile, suggests that this receptor may be implicated in modulating the afterdischarge during the egg-laying behavior.
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PMID:Functional characterization of a novel serotonin receptor (5-HTap2) expressed in the CNS of Aplysia californica. 1190 24