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)

The effects of 5-hydroxytryptamine (5-HT) on the release of gamma-aminobutyric acid (GABA) were examined in the longitudinal muscle-myenteric plexus (LM-MP) preparation of guinea-pig ileum. 5-HT increased the spontaneous release and inhibited the electrically-evoked release of [3H]-GABA. The 5-HT-evoked release was Ca2+-dependent and tetrodotoxin-sensitive, and was antagonized by (3 alpha-tropanyl)-1H-indole-3-carboxylic acid ester (ICS 205-930), but not by methysergide and ketanserin. The inhibitory effect of 5-HT was antagonized by methysergide, but not by ketanserin and ICS 205-930. 8-Hydroxy-2-(di-n-propylamino)tetralin mimicked the inhibitory effect of 5-HT. Thus, 5-HT may exert an excitatory effect on the enteric GABAergic neurone via the 5-HT3 receptor and an inhibitory effect via the 5-HT1A receptor.
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PMID:Dual effects of 5-hydroxytryptamine on the release of gamma-aminobutyric acid from myenteric neurones of the guinea-pig ileum. 281 20

The effect of serotonin [5-hydroxytryptamine (5-HT)] on pial venous tone of the pig was examined using in vitro tissue bath techniques. Isolated pial venous rings exhibited spontaneous rhythmic contractions (SRC) on mechanical stretching and/or applications of several vasoactive substances, including norepinephrine. On the other hand, KCl induced sustained active muscle tone (SAT) without SRC. The SRC induced by mechanical stretching were not affected by tetrodotoxin, nitro-L-arginine, alpha- and beta-adrenergic, histaminergic, and muscarinic receptor antagonists, indicating that the SRC in porcine pial veins are of myogenic origin. The SRC induced by stretching or applications of vasoactive substances and SAT induced by KCl were inhibited by 5-HT in a concentration-dependent manner. The inhibition was prevented by methysergide and methiothepin but not by ketanserin, propranolol, 3 alpha-tropanyl-1H-indole-3-carboxylic acid ester, hemoglobin, or nitro-L-arginine. The SRC and SAT were inhibited by 5-carboxamidotryptamine (5-CT), 8-hydroxy-2-di-N-propylaminotetralin HBr (8-OHDPAT), 1-[3-(trifluoromethyl)phenyl]piperazine (TFMPP), and 5-methoxytryptamine (5-MT), but not by sumatriptan, alpha-methylserotonin, or 2-methylserotonin. On the other hand, 5-CT, 8-OHDPAT, TFMPP, 5-MT, and sumatriptan constricted the porcine pial arteries exclusively. In 15% of pial venous preparations examined, 5-HT at low concentrations induced ketanserin-sensitive constrictions. These results indicate that the porcine pial venous smooth muscle contains multiple subtypes of 5-HT receptors. The 5-HT inhibition of SRC and SAT is predominant and is mediated by 5-HT1-like receptors, which, however, do not seem to correspond to 5-HT1A, 5-HT1B, 5-HT1C, 5-HT1D, 5-HT1E, or 5-HT1F receptor subtypes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Serotonin relaxes porcine pial veins. 816 Aug 3

The effects of several 5-hydroxytryptamine (5-HT) receptor antagonists on the anorectic effect of d-fenfluramine and the 5-HT2/5-HT1C agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) were examined in a dietary paradigm that appears to be sensitive to 5-HT-induced carbohydrate suppression. In this paradigm, deprived rats are provided with a nutritionally complete hydrated chow mash diet together with an optional carbohydrate supplement of powdered Polycose. Both d-fenfluramine and DOI produced a clear suppression of total energy intake and carbohydrate (Polycose) intake. However, the mechanisms underlying these effects are different. The effect of d-fenfluramine in this paradigm was attenuated by the 5-HT1/5-HT2 receptor antagonist metergoline and partially attenuated by the 5-HT1A/5-HT1B receptor antagonist (+/-)cyanopindolol. In contrast, d-fenfluramine's effect was not antagonised by the 5-HT2 receptor antagonist ketanserin, the 5-HT3 receptor antagonist (3 alpha-tropanyl)-1H-indole-3-carboxylic acid ester (ICS-205,930), the 5-HT2/5-HT1C receptor antagonist ritanserin, or the peripheral 5-HT receptor antagonist xylamidine. However, the effect of DOI in this paradigm was significantly attenuated by ketanserin but was not antagonised by either ritanserin or (+/-)cyanopindolol. Therefore, the suppressive effect of these two 5-HT drugs on total and Polycose intake appears to be mediated, respectively, by 5-HT1B/5-HT1C receptors (d-fenfluramine) and 5-HT2 receptors (DOI).
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PMID:5-HT and carbohydrate suppression: effects of 5-HT antagonists on the action of d-fenfluramine and DOI. 826 89