title: 5-HT1A-mediated lower lip retraction: effects of 5-HT1A agonists and antagonists.
abstract: This study investigated the production of lower lip retraction (LLR) in the rat by the 5-hydroxytryptamine1A (5-HT1A) agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) and the effect of the putative 5-HT1A antagonists pindolol and (1-(2-methoxy-phenyl)-4-[4-(2-phthalimido)-butyl]-piperazine (NAN190). 8-OH-DPAT (0.125-1.0 mg/kg, IP) caused a dose-related increase in LLR. Pindolol (10-40 mg/kg, IP) and NAN190 (2.5-10 mg/kg, IP) produced a dose-related block of 8-OH-DPAT-induced LLR. Pindolol (10-40 mg/kg, IP) when administered alone was also found to cause LLR, suggesting that pindolol behaves as a partial agonist in this model. This was not the case with NAN190 (2.5-10 mg/kg, IP), which failed to produce LLR; however, NAN190 (2.5-10 mg/kg, IP) produced a dose-related block of the pindolol-induced LLR. These results clearly demonstrate that the LLR model can be used to detect 5-HT1A agonists, partial agonists, and antagonists.
authors.affiliation: Lilly Research Centre, Eli Lilly & Co., Windlesham, Surrey, UK.
authors.forename: N A
authors.initials: NA
authors.lastname: Moore
authors.forename: G
authors.initials: G
authors.lastname: Rees
authors.forename: G
authors.initials: G
authors.lastname: Sanger
authors.forename: L
authors.initials: L
authors.lastname: Perrett
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D008046:Lip / Q000502:physiology; D008297:Male; D010869:Pindolol / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
chemical_list: D010879:Piperazines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C058895:1-(2-methoxyphenyl)-4-(4-(2-phthalimido)butyl)piperazine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D010869:Pindolol