Differential effects of 5-hydroxytryptamine1a selective drugs on the 5-HT behavioral syndrome.
The effects of 8-hydroxy-2-(di-n-propyl-amino) tetralin (8-OH-DPAT), 5-methoxy-N,N-dimethyltryptamine (5-MeODMT), buspirone and isapirone were examined at 5-hydroxytryptamine1A (5-HT1A) binding sites and on the 5-HT behavioral syndrome in the rat. 8-OH-DPAT, 5-MeODMT, buspirone and isapirone are all potent inhibitors of 3H-8-OH-DPAT binding to rat brain membranes (Ki values = 1.9-13 nM). However, these drugs have differential effects on the 5-HT behavioral syndrome. 8-OH-DPAT, 5-MeODMT and buspirone induce hindlimb abduction, flattened body posture and Straub tail. Isapirone induces only a slight flattening of body posture. By contrast, 8-OH-DPAT and 5-MeODMT, but not buspirone and isapirone, and isapirone, also induce forepaw treading, head-weaving and tremor. However, both buspirone and isapirone antagonize the induction of these three behaviors by 8-OH-DPAT or 5-MeODMT. These data show that 8-OH-DPAT and 5-MeODMT are "full agonists" in relation to six components of the 5-HT behavioral syndrome. Buspirone and isapirone, on the other hand, act as "antagonists" in relation to forepaw treading, head-weaving and tremor. Therefore, these data suggest that specific components of the 5-HT behavioral syndrome are mediated by 5-HT1A receptors.
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002065:Buspirone; D004305:Dose-Response Relationship, Drug; D008732:Methoxydimethyltryptamines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology*; D013764:Tetrahydronaphthalenes / Q000378:metabolism / Q000494:pharmacology; D013997:Time Factors
D008732:Methoxydimethyltryptamines; D011743:Pyrimidines; D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; D012701:Serotonin; C043077:ipsapirone; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D002065:Buspirone