Eleven ergot compounds were competed against [3H]-ketanserin-labelled 5-HT2 receptors in rat and human cortex. Four of the ergots are selective for rat 5-HT2 receptors--mesulergine, methysergide, nicergoline and metergoline, whereas pergolide, d-lysergic acid, ergonovine, ergotamine, d-lysergic acid diethylamide, lisuride and dihydroergotamine display selectivity for human 5-HT2 receptors....
The interactions of the indolealkylamine N,N-dimethyltryptamine (DMT) with 5-hydroxytryptamine1A (5-HT1A) and 5-HT2 receptors in rat brain were analyzed using radioligand binding techniques and biochemical functional assays. The affinity of DMT for 5-HT1A sites labeled by [3H]-8-hydroxy-2-(di-n-propylamino)tetralin ([3H]-8-OH-DPAT) was decreased in the presence of 10(-4) M GTP, suggesting...
This study examined the [3H]5-HT-releasing properties of 3,4-methylenedioxymethamphetamine (MDMA) and related agents, all of which cause significant release of [3H]5-HT from rat brain synaptosomes. 5-HT uptake blockers dose dependently block MDMA-induced [3H]5-HT release. The EC50s of the uptake drugs in blocking MDMA-induced release correlate with their affinity for the 5-HT uptake site...
3,4-Methylenedioxymethamphetamine (MDMA; 'Ecstasy') is a known neurotoxin to 5-hydroxytryptamine (5-HT) nerve terminals. Recent studies have suggested that endogenous dopamine (DA) and/or 5-HT may mediate the MDMA-induced neurotoxicity. The central monoamine stores of rats were significantly decreased with reserpine (5 mg/kg) prior to toxic injections of MDMA. Rats given MDMA (30 mg/kg)...
The binding affinities of four hallucinogenic agents were analyzed at nine neurotransmitter binding sites in human cortex. d-Lysergic acid diethylamide (d-LSD), N,N-dimethyltryptamine (DMT), 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) and 1-(2,5-dimethoxy-4-bromophenyl)-2-aminopropane (DOB) display highest affinity for the recently identified "DOB binding site" labeled by 77Br-R(-)DOB....
The binding affinities of 3 ring-substituted amphetamine compounds were determined at 9 neurotransmitter binding sites in human cortex. (+/-)-3,4-Methylenedioxyamphetamine (MDA), (+/-)-3,4-methylenedioxyethamphetamine (MDE), and (+/-)-3,4-methylenedioxymethamphetamine (MDMA or 'Ecstasy') all display highest affinity (approximately 1 microM) for the recently identified 'DOB binding site' labeled...
The interactions of the indolealkylamine hallucinogen d-lysergic acid diethylamide (d-LSD) and two phenalkylamine hallucinogens, 2,5-dimethoxy-4-bromoamphetamine (DOB) and 2,5-dimethoxy-4-iodoamphetamine (DOI), with 5-hydroxytryptamine2 (5-HT2) receptors were analyzed in rat cortex using both radioligand binding techniques and biochemical measurements of phosphatidylinositol (PI) turnover....
Recent studies suggest that 3,4-methylenedioxymethylamphetamine (MDMA), when administered subcutaneously, is toxic to central serotonergic neurons in rats. Because humans typically self-administer this drug orally, we compared this route to the s.c. route of administration. Orally administered MDMA produced a dose-related depletion of serotonin comparable to that produced by the s.c. route....
R(-)-2,5-Dimethoxy-4-77Br-amphetamine [77Br-R(-)DOB], a radioligand of high specific activity (1500 +/- 200 Ci/mmol), was used to label membrane-associated recognition sites in rat brain. 77Br-R(-)DOB sites were of high affinity (KD = 0.19 nM) but low density (Bmax = 0.32 pmol/g tissue) in rat brain preparations. Competition experiments show that both 5-hydroxytryptamine (5-HT) and 5-HT2...
Radioligand binding studies were used to analyze the interactions of six "prosexual" drugs with 5-hydroxytryptamine1A (5-HT1A) and alpha 2-adrenergic receptors in rat brain membranes. Three drugs that facilitate seminal emissions and/or ejaculations [8-hydroxy-2-n-propylaminotetralin (8-OH-DPAT), 5-methoxy-dimethyltryptamine, and RDS-127] are potent and selective inhibitors of [3H]8-OH-DPAT...
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)....