scholarly journals Pharmacological Characterization of 5-Hydroxytryptamine-Receptor Subtypes in Circular Muscle from the Rat Stomach

2007 ◽  
Vol 30 (3) ◽  
pp. 508-513 ◽  
Author(s):  
Tohru Komada ◽  
Shingo Yano
Keyword(s):  
Circular Muscle ◽  
Receptor Subtypes ◽  
Rat Stomach ◽  
Pharmacological Characterization

Pharmacological Characterization of an Adenylyl Cyclase-Coupled 5-HT Receptor in Aplysia: Comparison With Mammalian 5-HT Receptors

2003 ◽  
Vol 89 (3) ◽  
pp. 1440-1455 ◽  
Author(s):  
Jonathan E. Cohen ◽  
Chiadi U. Onyike ◽  
Virginia L. McElroy ◽  
Allison H. Lin ◽  
Thomas W. Abrams
Keyword(s):  
Adenylyl Cyclase ◽  
Rank Order ◽  
Physiological Saline ◽  
Receptor Subtypes ◽  
Pharmacological Profile ◽  
Pharmacological Characterization ◽  
Firing Properties ◽  
Stimulation Of

We attempted to identify compounds that are effective in blocking the serotonin (5-hydroxytryptamine, 5-HT) receptor(s) that activate adenylyl cyclase (AC) in Aplysia CNS. We call this class of receptor 5-HTapAC. Eight of the 14 antagonists tested were effective against 5-HTapAC in CNS membranes with the following rank order of potency: methiothepin > metergoline ∼ fluphenazine > clozapine > cyproheptadine ∼ risperidone ∼ ritanserin > NAN-190. GR-113808, olanzapine, Ro-04-6790, RS-102221, SB-204070, and spiperone were inactive. Methiothepin completely blocked 5-HT stimulation of AC with a K b of 18 nM. Comparison of the pharmacological profile of the 5-HTapAC receptor with those of mammalian 5-HT receptor subtypes suggested it most closely resembles the 5-HT6 receptor. AC stimulation in Aplysia sensory neuron (SN) membranes was also blocked by methiothepin. Methiothepin substantially inhibited two effects of 5-HT on SN firing properties that are mediated by a cAMP-dependent reduction in S-K+ current: spike broadening in tetraethylammonium/nifedipine and increased excitability. Consistent with cyproheptadine blocking 5-HT stimulation of AC, cyproheptadine also blocked the 5-HT-induced increase in SN excitability. Methiothepin was less effective in blocking AC-mediated modulatory effects of 5-HT in electrophysiological experiments on SNs than in blocking AC stimulation in CNS or SN membranes. This reduction in potency appears to be due to effects of the high ionic strength of physiological saline on the binding of this antagonist to the receptor. Methiothepin also antagonized AC-coupled dopamine receptors but not AC-coupled small cardioactive peptide receptors. In conjunction with other pharmacological probes, this antagonist should be useful in analyzing the role of 5-HT in various forms of neuromodulation in Aplysia.

Biochemical and pharmacological characterization of SR 48692: Evidence for neurotensin receptor subtypes

Neuropeptides ◽  
1994 ◽  
Vol 26 ◽  
pp. 36
Author(s):  
J.P. Terranova ◽  
F. Oury-Donat ◽  
D. Gully ◽  
G. Le Fur ◽  
P. Soubrié
Keyword(s):  
Receptor Subtypes ◽  
Pharmacological Characterization ◽  
Neurotensin Receptor
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