5-HT antagonists and blockade of neuronal (5-HT) receptors on ganglion cells.
Potential changes in superior cervical ganglion cells evoked by 5-HT or the nicotinic agonist, dimethyl-phenyl piperazinium (DMPP), were recorded using the sucrose-gap method and a number of putative 5-HT antagonists tested for potency and selectivity. Selective blockade of 5-HT responses was produced by 5-HT itself and, in increasing order of potency, by cocaine, metoclopramide and quipazine. A non-selective blockade was observed with bufotenine and d-tubocurarine. Substances which had no effect on 5-HT responses included methysergide and other compounds related to LSD, cinanserin, cyproheptadine, phenylbiguanide and morphine. The results provide further information about the 5-HT receptor on sympathetic ganglion cells and support the view that this receptor is distinct from neuronal receptors in the myenteric plexus and on cholinergic nerve terminals.
D000081:Acetamides / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000588:Amines / Q000494:pharmacology; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D004246:Dimethylphenylpiperazinium Iodide / Q000494:pharmacology; D005728:Ganglia, Sympathetic / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D008238:Lysergic Acid Diethylamide / Q000031:analogs & derivatives / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects; D010879:Piperazines / Q000494:pharmacology; D011817:Rabbits; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013618:Tachyphylaxis
D000081:Acetamides; D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D000588:Amines; D000779:Anesthetics, Local; D010879:Piperazines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D012701:Serotonin; D004246:Dimethylphenylpiperazinium Iodide; D008238:Lysergic Acid Diethylamide