D-lysergic Acid Diethylamide Research Articles

Club Drug Use and Dependence among Young Adults Recruited through Time-Space Sampling

Ketamine, methylenedioxymethamphetamine (MDMA/ecstasy), cocaine, gamma-hydroxybutyrate (GHB), methamphetamine, and d-lysergic acid diethylamide (LSD/acid) have been identified as "club drugs" because of their link to club culture among young adults. Yet little is known about users' demographic differences in the prevalence of club drugs. This study sought to provide a comprehensive profile of users' demographic differences in prevalence of club drug use and dependence. Using time-space sampling, a stratified sample of 400 18- to 29-year-old club-going young adults was recruited into the Club Drugs and Health Project. Though participants reported using an array of club drugs, almost all participants (90.0%) were cocaine users. Although there were several sexual orientation and gender differences in recent drug exposure, patterns of use (measured in days) were fairly similar across gender, sexual orientation, and age. Finally, a majority of individuals (58.5%) met or exceeded criteria for club drug dependence, with most (61.7%) indicating cocaine was the one drug causing them significant problems. Cocaine is a major drug in club culture. It is essential to develop culturally appropriate drug education and prevention initiatives for young adults using club drugs.

Psychedelic Psychiatry: LSD from Clinic to Campus by Erica Dyck

Health& History 1112 2009 159 has to sort through a lot of other stuff to get it.He has some trouble keeping onmessage, often diverting tonon-related areas of psychiatric history. Then, we have to deal with his well-known opinions of the dreaded drug companies who are undoubtedly a part of the history, but could have been dealt with more objectively. I rather enjoyed his interludes into the nineteenth-century asylum records at his disposal, even if theywere not too relevant at times. The book is a scholarly one for all that.Healy's wide knowledge of the facts of the history is impressive and the list of references is one area that I will value. I would still like to see how the non psychiatrist historian of psychiatry Edward Shorter would do it. PAUL SKERRITT UNIVERSITY OFWESTERN AUSTRALIA /JOONDALUP HEALTH CAMPUS Erica Dyck, PsychedelicPsychiatry:LSD from Clinic toCampus (Baltimore, MD: Johns Hopkins University Press, 2008). ISBN 9780801889943 (HQ. 16halftones, 216 pp. LSD (d-lysergic acid diethylamide) is synonymous with the term 'psychedelic,' a term coined by Dr Humphrey Osmond, the chief person of interest in thisbook. It also elicits two central but opposing associations: the 1960s 'Turn on, tune in, drop out' counter-culture movement, and the recollections of warnings of irreparable brain and chromosome damage, and stories of 'tripping' students leaping out of a windows from high-rise apartments or baby-sitters cooking babies in ovens, mistaking them for roasts. This book is a quest to understand this dichotomy. It seeks to do so by researching the introduction of LSD as a therapeutic tool for the psychotherapy of people with schizophrenia and alcoholism, in a small country town in theprairies of Canada?Weyburn, Saskatechewan (as incongruent as that may seem), by Humphrey Osmond and his colleague Abram Hoffer. As a consequence of their research, some of which initially entailed increasing the treating psychiatrists' empathy and understanding of their patients' experiences through their own experiments with LSD, Osmond and Hoffer tried to bring together biological research into psychiatry with phenomenology. They 160 BOOKREVIEWS envisioned a new psychiatry, solving the mind-body issue by approaching their patients with methods that directly altered phenomenology through chemistry. Unfortunately for them, the trauma of the thalidomide medical disaster, the success of the neuroleptics, the general futility of psychodynamics to deal with mental illness more serious than the 'worried wealthy,' and the largely political demonisation of LSD, pushed psychiatry into the use of purely biological double-blind placebo controlled trial designs with easily objectified measures. Their dreams of a unified mind-body approach did not to come to fruition. Dyck's retelling of this period of psychiatric history falls short of what Imay have wished for in a couple of ways. While quite correctly pointing out thatOsmond and Hoffer had a fairly significant impact on international psychiatry in the fifties and early sixties, this point was not well-documented in the book. Indeed, there are a number of articles investigating other 'psychedelic' drugs as potential therapies?including cannabis and MDMA?in psychotherapy in the sixties, which could have been usefully referred to in the book. Besides being one of the first(ifnot thevery first) author to suggest a biochemical theory of schizophrenia and a very early proponent of a possible genetic link in schizophrenia, Osmond was a prolific writer producing influential articles with people such as Julian Huxley on a diversity of biological issues in psychiatry, which are described, but not so well documented, in the book. Itwould have been good to include some of these references in the book itself, to support this contention empirically. The book may also have been greatly improved if the specific example of the therapeutic use of LSD and its stifling through largely political rather thanmedical reasons were put into a wider context. There were similar experiences in the late 1800s (and again in the early 2000s) in the UK with cannabis, where early evidence of a therapeutic use in the treatment of insanity (1870) was ignored, as were findings thatganja did not worsen insanity, in an attempt to limit the availability of ganja in the Indian colonies as a tool of colonialism. J.H. Mills' recent study...

Agonist-directed trafficking of signalling at serotonin 5-HT 2A, 5-HT 2B and 5-HT 2C-VSV receptors mediated Gq/11 activation and calcium mobilisation in CHO cells

Several examples of agonist-directed trafficking of receptor signalling at 5-HT 2A and 5-HT 2C receptors have been reported that involve independent downstream transduction pathways. We now report the functional selectivity of a series of chemically diverse agonists at human (h)5-HT 2A, h5-HT 2B and h5-HT 2C-VSV by examining two related responses, the upstream activation of Gq/11 proteins in comparison with its associated cascade of calcium mobilisation. At the h5-HT 2A receptor, d-lysergic acid diethylamide (LSD) and the antiparkinsonian agents lisuride, bromocriptine and pergolide exhibit a higher potency for Gq/11 activation than calcium release in contrast with all the other tested ligands such as 5-HT, mCPP and BW723C86, that show an opposite preference of signalling pathway. Comparable observations are made at h5-HT 2B and h5-HT 2C-VSV receptors, suggesting a similar mechanism of functional selectivity for the three serotonin receptors. Interestingly, the non-hallucinogenic compound lisuride behaves as a partial agonist for both Gq/11 activation and calcium release at the three 5-HT 2 receptors, in contrast with DOI, LSD, pergolide and bromocriptine, which are known to provoke hallucinations, and behave as more efficacious agonists. Hence, a functional selectivity for Gq/11 activation together with a threshold of efficacy at h5-HT 2A (and possibly h5-HT 2B and/or h5-HT 2C-VSV) may contribute to hallucinogenic liability. Thus, our results extend the notion of agonist-directed trafficking of receptor signalling to all the 5-HT 2-receptor family and indicate that measures of Gq/11 activation versus calcium release may be useful to identify more effective therapeutic drugs with limited side effects.

Development of a scintillation proximity assay binding method for the human 5-hydroxytryptamine 6 receptor using intact cells

We describe the first validated scintillation proximity assay (SPA) binding method for quantitation of 3H-labeled d-lysergic acid diethylamide (LSD) binding to recombinant human 5-hydroxytryptamine 6 (5-HT 6) receptors expressed in Chinese hamster ovary (CHO)–Dukx and HeLa cells. The assay was developed using intact cells as a receptor source because membrane fractions derived from these cells failed to discern specific binding from a high level of nonspecific binding. The pharmacological binding profile of seven 5-HT 6 agonists and antagonists using intact CHO–Dukx/5-HT 6 cells in the SPA format was similar to data obtained from a filtration binding assay using HeLa/5-HT 6 membranes. K i values and rank order of potencies obtained in the SPA format were consistent with published filtration data as follows: SB-271046 ( K i = 1.9 nM) > methiothepin ( K i = 6.2 nM) > mianserin ( K i = 74.3 nM) > 5-methoxytryptamine (5-MeOT, K i = 111 nM) > 5-HT ( K i = 150 nM) > ritanserin ( K i = 207 nM) > 5-carboxamidotryptamine (5-CT, K i = 704 nM). Additional evaluation with four antipsychotics demonstrated strong agreement with previous literature reports. A high specific binding signal and low assay variability, as determined by Z′ = 0.81 ± 0.017, make the SPA format amenable to automation and higher throughput; hence, this assay can be a viable alternative to the more labor-intensive filtration and centrifugation methods.

Determination of Illicit Drugs and their Metabolites in Human Urine by Liquid Chromatography Tandem Mass Spectrometry Including Relative Ion Intensity Criterion

A method, using 0.5 mL of urine, was developed for the simultaneous determination of ecgonine methyl ester, benzoylecgonine, morphine, codeine, 6-acetylmorphine, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and d-lysergic acid diethylamide (LSD). The analysis was performed by liquid chromatography with tandem mass spectrometry, after solid-phase extraction in the presence of their deuterated analogues. Reversed-phase separation on an Atlantis dC18 column was achieved in 12.5 min, under gradient conditions. The method was fully validated, including linearity (1-2000 microg/L for ecgonine methyl ester, benzoylecgonine, 6-acetylmorphine, methamphetamine, MDMA, and EDDP; 2-2000 microg/L for morphine, codeine, MDA, and methadone; 2-1000 microg/L for amphetamine, and 0.2-100 microg/L for LSD; r(2)>0.99); recovery (>65%), within-day and between-day precision, and accuracy (CV and MRE<15%); limit of detection (0.1 microg/L for LSD, 0.5 microg/L for ecgonine methyl ester, benzoylecgonine, methamphetamine, MDMA, 6-monoacetylmorphine, and EDDP, and 1 microg/L for amphetamine, MDA, morphine, and methadone); quantitation (lowest level of the calibration curve); relative ion intensities, freeze-and-thaw stability, and matrix effect. The procedure showed to be sensitive and specific, and was applied to real cases and quality control samples from a quality control program.

Acid trip: The history of LSD -- the original psychedelic drug

In April 1943, Dr Albert Hofmann, a Swiss biochemist, dissolved a few micrograms of a newlysynthesized drug, d-lysergic acid diethylamide (LSD), in a glass of water and drank it. Three-quarters of an hour later, he recorded a growing dizziness, some visual disturbances and a marked desire to laugh. After about an hour he asked his assistant to call a doctor and accompany him home from his research laboratory at the Sandoz Pharmaceutical Company in Zurich, Switzerland. He then climbed onto his bicycle and went on a surreal journey. In Hofmann's mind he was not on the familiar road that led home, but rather a street painted by Salvador Dali, a funhouse roller coaster. When he arrived home a doctor was ordered and found Hofmann physically fine, but mentally distraught.

Flashback to the 1960s: LSD in the treatment of autism

Between 1959 and 1974, several groups of researchers issued reports on the use of d-Lysergic Acid Diethylamide (LSD) in the treatment of children with autism. This paper reviews that literature to consider how the authors justified these studies, as well as their methods, results, and conclusions. The justification for using LSD was often based on the default logic that other treatment efforts had failed. Several positive outcomes were reported with the use of LSD, but most of these studies lacked proper experimental controls and presented largely narrative/descriptive data. Today there is renewed interest in the use of psychedelic drugs for therapeutic purposes. While this resurgence of research has not yet included children with autism, this review of the LSD studies from the 1960s and 1970s offers important lessons for future efforts to evaluate new or controversial treatments for children with autism.

5-Hydroxytryptamine (Serotonin)2AReceptors in Rat Anterior Cingulate Cortex Mediate the Discriminative Stimulus Properties ofd-Lysergic Acid Diethylamide

d-Lysergic acid diethylamide (LSD), an indoleamine hallucinogen, produces profound alterations in mood, thought, and perception in humans. The brain site(s) that mediates the effects of LSD is currently unknown. In this study, we combine the drug discrimination paradigm with intracerebral microinjections to investigate the anatomical localization of the discriminative stimulus of LSD in rats. Based on our previous findings, we targeted the anterior cingulate cortex (ACC) to test its involvement in mediating the discriminative stimulus properties of LSD. Rats were trained to discriminate systemically administered LSD (0.085 mg/kg s.c.) from saline. Following acquisition of the discrimination, bilateral cannulae were implanted into the ACC (AP, +1.2 mm; ML, +/-1.0 mm; DV, -2.0 mm relative to bregma). Rats were tested for their ability to discriminate varying doses of locally infused LSD (0.1875, 0.375, and 0.75 microg/side) or artificial cerebrospinal fluid (n = 3-7). LSD locally infused into ACC dose-dependently substituted for systemically administered LSD, with 0.75 microg/side LSD substituting completely (89% correct). Systemic administration of the selective 5-hydroxytryptamine (serotonin) (5-HT)(2A) receptor antagonist R-(+)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidine-methanol (M100907; 0.4 mg/kg) blocked the discriminative cue of LSD (0.375 microg/side) infused into ACC (from 68 to 16% drug lever responding). Furthermore, M100907 (0.5 microg/microl/side) locally infused into ACC completely blocked the stimulus effects of systemic LSD (0.04 mg/kg; from 80 to 12% on the LSD lever). Taken together, these data indicate that 5-HT(2A) receptors in the ACC are a primary target mediating the discriminative stimulus properties of LSD.

‘Hitting Highs at Rock Bottom’: LSD Treatment for Alcoholism, 1950–1970

In the 1950s, researchers in the Canadian province of Saskatchewan began treating alcoholics with d-lysergic acid diethylamide (LSD) and achieved significant rates of recovery. Psychiatrists, including Humphry Osmond who coined the term 'psychedelic' while working in Saskatchewan, believed that the successful treatment of alcoholism with biochemical means would scientifically prove that the condition was a disease and not the result of a weak or immoral character. Initial experiments demonstrated unprecedented rates of abstinence among alcoholics treated with LSD. The approach gained support from the provincial government, local chapters of Alcoholics Anonymous and the Bureau of Alcoholism, all of which collaborated in a public campaign that supported LSD treatments. Although Alcoholics Anonymous endorsed psychedelic therapy, the Addictions Research Foundation did not. The leading Canadian authority on addictions disputed the findings in Saskatchewan and challenged these advocates of psychedelic treatments to conduct trials with proper controls. Despite subsequent efforts to demonstrate that the success of psychedelic therapy relied on both medical and non-medical factors, the treatment failed to satisfy current medical methodology, embodied in controlled trials. By the late 1960s, LSD had become a popular recreational drug and gained media attention for its association with counter cultural youth, social disobedience and anti-authoritarian attitudes. All this served further to erode support for its clinical status.

TRIP OF A CENTURY

LATE LAST MONTH, THE UNIVERSITY of Zurich hosted a symposium in celebration of the 100th birthday of one of its most illustrious alumni, Albert Hofmann. More than 60 years ago, on a spring day while World War II raged in Europe and the Pacific, Hofmann synthesized perhaps the most mind-bending chemical of all time: the psychomimetic agent LSD, formally known as D-lysergic acid diethylamide. Hofmann got some of his first inklings of the drug's powers while riding his bike home from his laboratory at the pharmaceutical giant Sandoz in Basel, Switzerland. Hofmann, born on Jan. 11,1906, first synthesized LSD in 1938 as part of a systematic investigation of dozens of derivatives of alkaloids made by ergot, a poisonous fungus that infects grains and grasses. Other ergot alkaloid derivatives from Hofmann's research program had shown strong effects on blood pressure and vasodilation, and these led to clinically effective medicines for treating ...

Concurrent use of methamphetamine, MDMA, LSD, ketamine, GHB, and flunitrazepam among American youths

Background The magnitude and the characteristics of the use of methamphetamine, MDMA (Ecstasy), LSD ( d-lysergic acid diethylamide), ketamine, GHB (gamma-hydroxybutyrate), and flunitrazepam (Rohypnol) were examined in a probability sample of the U.S. civilian population that included multiethnic urban, suburban, and rural youths aged 16–23 ( N = 19,084). Methods Data were drawn from the National Survey on Drug Use and Health (NSDUH). Logistic regression analyses were conducted to identify the characteristics associated with the use of each of these drugs and of multiple drugs. Results Approximately 20% of youths aged 16–23 reported having ever used one or more of these drugs. Less than 1% of club drug users used club drugs only, and 82% of them had ever used three or more drug classes. Females were more likely than males to report using multiple club drugs. Recent users of methamphetamine were most likely to be females and adolescents aged 16 or 17. Recent users of MDMA tended to be young adults aged 18–21 and residents of metropolitan areas. Most recent users of LSD were adolescents aged 16–19 and those in low-income families. Ketamine users were primarily employed youths. Staying in school and getting married were associated with decreased odds of club drug use. Club drug use was highly associated with the presence of criminal behaviors and recent alcohol abuse or dependence. Conclusions Adolescents are more likely than young adults to use multiple drugs. The clustering of multidrug use and alcohol use disorder is a cause of concern.

Flashback: Psychiatric Experimentation with LSD in Historical Perspective

In the popular mind, d-lysergic acid diethylamide (LSD) research in psychiatry has long been associated with the CIA-funded experiments conducted by Ewen Cameron at the Allen Memorial Institute in Montreal, Quebec. Despite this reputation, a host of medical researchers in the post World War II era explored LSD for its potential therapeutic value. Some of the most widespread trials in the Western world occurred in Saskatchewan, under the direction of psychiatrists Humphry Osmond (in Weyburn) and Abram Hoffer (in Saskatoon). These medical researchers were first drawn to LSD because of its ability to produce a "model psychosis." Their experiments with the drug that Osmond was to famously describe as a "psychedelic" led them to hypothesize and promote the biochemical nature of schizophrenia. This brief paper examines the early trials in Saskatchewan, drawing on hospital records, interviews with former research subjects, and the private papers of Hoffer and Osmond. It demonstrates that, far from being fringe medical research, these LSD trials represented a fruitful, and indeed encouraging, branch of psychiatric research occurring alongside more famous and successful trials of the first generation of psychopharmacological agents, such as chlropromazine and imipramine. Ultimately, these LSD experiments failed for 2 reasons, one scientific and the other cultural. First, in the 1950s and early 1960s, the scientific parameters of clinical trials shifted to necessitate randomized controlled trials, which the Saskatchewan researchers had failed to construct. Second, as LSD became increasingly associated with student riots, antiwar demonstrations, and the counterculture, governments intervened to criminalize the drug, restricting and then terminating formal medical research into its potential therapeutic effects.

Serotonergic and dopaminergic influence of the duration of embryogenesis and intracapsular locomotion of Lymnaea stagnalis L.

The role of the dopaminergic and serotonergic system was studied during the embryonic development of the pond snail Lymnaea stagnalis, with special attention to the effect of dopamine and serotonin as well as their agonists and antagonists on the rotation of the veliger larvae, and to the effect of precursors and inhibitors of the synthetizing enzymes on the duration of the embryonic life. Serotonin, D-lysergic acid diethylamide and N,N-dimethyltryptamine increased at a concentration of 1 microM the rotation by 50%, 90% and 87% respectively, and among them D-Lysergic acid diethylamide was found to be the most potent agonist. Other serotonergic agonists and antagonists enhanced the frequency of the rotation (from 165% to 355%) at higher threshold concentrations in the following rank order: methysergid > tryptamine > 2,5-dimethoxy-4-iodoamphetamine > 5-carboxyamidotryptamine > bromo-lysergic acid diethylamide > 7-methyltryptamine. Application of 1-(2-methoxyphenyl) piperazine decreased the rotation by 76%. The reuptake inhibitor desipramine completely blocked the rotation and killed the embryos. Dopaminergic agonists accelerated the rotation by 62% to 233%, and their effect was ranged as follows: dopamine > apomorphine > m-tyramine approximately equal to p-tyramine. Chlorpromazine at 100 microM concentration killed the embryos. At a concentration of 100 microg/ml, tyrosine, the precursor of DA, slowed down the embryonic development by increasing the duration of the embryonic life from 8 to 10 days. Decarboxylase inhibitors, alpha-methyl-3,4-dihydroxyphenyl-alanine (25 microg/ml) and m-hydroxybenzylhydrazin (5 microg/ml), killed 50% of the embryos, meanwhile the rest hatched ten days later, compared to the control animals. The development was partially blocked by the serotonin precusor L-tryptophane (50 microg/ml). Trytophan hydroxylase blocker, p-chlorphenylalanine (50 microg/ml) resulted in a distortion of the body pattern of the embryos, and prevented the hatching of most (95%) of the animals.

Boletus Manicus Heim

Boletus manicus Heim [Boletaceae] is a species of fungus found in Papua New Guinea. It is reported to have psychoactive properties. The chemistry of this species is poorly understood. The available chemical data indicates that B. manicus contains trace amounts of three unidentified indolic substances. The chemical structure of these substances has not yet been determined. For these indoles to be active in trace amounts they must be as potent as d-lysergic acid diethylamide (LSD).

Role of the serotonin 5-HT(2A) receptor in learning.

This study reviews the role of the serotonin 5-HT2A receptor in learning as measured by the acquisition of the rabbit's classically conditioning nictitating membrane response, a component of the eyeblink response. Agonists at the 5-HT2A receptor including LSD (d-lysergic acid diethylamide) enhanced associative learning at doses that produce cognitive effects in humans. Some antagonists such as BOL (d-bromolysergic acid diethylamide), LY53,857, and ketanserin acted as neutral antagonists in that they had no effect on learning, whereas others (MDL11,939, ritanserin, and mianserin) acted as inverse agonists in that they retarded learning through an action at the 5-HT2A receptor. These results were placed in the context of what is known concerning the anatomical distribution and electrophysiological effects of 5-HT2A receptor activation in frontal cortex and hippocampus, as well as the role of cortical 5-HT2A receptors in schizophrenia. It was concluded that the 5-HT2A receptor demonstrates constitutive activity, and that variations in this activity can produce profound alterations in cognitive states.

Problems encountered when testing for LSD in a regional medium secure unit

Aims and MethodBetween 1998 and 2000, a surprisingly high number of positive results was noticed in our regional medium secure unit when testing for D-lysergic acid diethylamide (LSD). This led to an investigation of possible factors involved. It was felt that the testing protocol, particularly the use of a single, non-isotopic homogeneous immunoassay without routine further confirmatory testing, was largely to blame for what seemed to be a high incidence of false positives. On two different occasions, samples from each patient were sent, on the same day, to two different laboratories. At the first laboratory, only one test method was used and at the second one test plus two confirmatory tests were carried out.ResultsOut of a total of 23 patients tested on two separate occasions, the first laboratory gave three positive results the first time and three positive results the second, while the second laboratory gave only one positive result on the second occasion that samples were sent and none on the first. This reinforces the belief that, without adequate confirmatory analysis, many psychiatric and non-psychiatric prescribed drugs can give false positives.Clinical ImplicationsPositive LSD results should be confirmed by at least one, preferably chromatographic, alternative method. A protocol for testing and reporting LSD in psychiatric patients should be considered in order to minimise the risk of obtaining false-positive results which have negative clinical, legal and psychological repercussions.

The hallucinogen d-lysergic acid diethylamide ( d-LSD) induces the immediate-early gene c-Fos in rat forebrain

The hallucinogen d-lysergic acid diethylamide ( d-LSD) evokes dramatic somatic and psychological effects. In order to analyze the neural activation induced by this unique psychoactive drug, we tested the hypothesis that expression of the immediate-early gene product c-Fos is induced in specific regions of the rat forebrain by a relatively low, behaviorally active, dose of d-LSD (0.16 mg/kg, i.p.); c-Fos protein expression was assessed at 30 min, and 1, 2 and 4 h following d-LSD injection. A time- and region-dependent expression of c-Fos was observed with a significant increase ( P<0.05) in the number of c-Fos-positive cells detected in the anterior cingulate cortex at 1 h, the shell of the nucleus accumbens at 1 and 2 h, the bed nucleus of stria terminalis lateral at 2 h and the paraventricular hypothalamic nucleus at 1, 2 and 4 h following systemic d-LSD administration. These data demonstrate a unique pattern of c-Fos expression in the rat forebrain following a relatively low dose of d-LSD and suggest that activation of these forebrain regions contributes to the unique behavioral effects of d-LSD.

Differential activation of Gq/11 and Gi(3) proteins at 5-hydroxytryptamine(2C) receptors revealed by antibody capture assays: influence of receptor reserve and relationship to agonist-directed trafficking.

As determined by a guanosine 5'-O-(3-[(35)S]thio)triphosphate ([(35)S]GTPgammaS) binding assay, which does not distinguish G protein subtypes, 5-hydroxytryptamine (5-HT) and 2(S)- 1-(6-chloro-5-fluoro-1H-indol-1-yl)-2-propanamine fumarate (Ro600175) behaved as full agonists at human 5-HT(2C) (h5-HT(2C)) receptors (VSV isoform) stably expressed in Chinese hamster ovary (CHO) cells, whereas 1-2,5-dimethoxy-4-iodophenyl-2-aminopropane (DOI), d-lysergic acid diethylamide (LSD), and lisuride exhibited partial agonist properties. After treatment with pertussis toxin to uncouple 5-HT(2C) receptors from Gi/Go but not Gq/11, DOI and LSD were as efficacious as 5-HT and Ro600175 in stimulating [(35)S]GTPgammaS binding, whereas lisuride still exhibited low efficacy (40%). Correspondingly, in a scintillation proximity assay employing specific antibodies against Gq/11, 5-HT, Ro600175, DOI, and LSD behaved as high-efficacy agonists, whereas lisuride showed efficacy of 36%. In contrast, when employing a specific antibody recognizing Gi(3), DOI and LSD were less efficacious (80 and 30%, respectively) than 5-HT and Ro600175, and lisuride was inactive. Agonist actions were specifically mediated by h5-HT(2C) receptors inasmuch as the selective 5-HT(2C) antagonist SB242,084 blocked [(35)S]GTPgammaS binding at both Gq/11 and Gi(3). Agonist potency for stimulation of Gi(3) was ~6- to 8-fold less than for Gq/11, indicating that the latter was preferentially engaged by h5-HT(2C) receptors. Inactivation of h5-HT(2C) receptors with the alkylating agent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline did not modify the efficacy of 5-HT, Ro600175, and DOI at Gq/11, whereas their efficacies were substantially reduced at Gi(3), indicating a greater receptor reserve for the former. Finally, the preferential activation of Gq/11 versus Gi(3) by DOI, LSD, and lisuride was diminished in the presence of lower receptor number. In conclusion, h5-HT(2C) receptors couple to both Gq/11 and Gi(3) in CHO cells, and efficacy for G protein subtype activation is both ligand- and receptor reserve-dependent.

5-HT 2A receptor-stimulated phosphoinositide hydrolysis in the stimulus effects of hallucinogens

The role of 5-HT 2A-mediated stimulation of phosphoinositide hydrolysis in the discriminative effects of hallucinogens was investigated in PC12 cells stably expressing the rat 5-HT 2A receptor (PC12-5-HT 2A cells). The hallucinogenic compounds, d-lysergic acid diethylamide (LSD), (−)2,5-dimethoxy-4-methylamphetamine (DOM), psilocybin, N, N-dimethyltryptamine (DMT), 5-methoxy- N, N-dimethyltryptamine (MDMT) and N, N-diethyltryptamine (DET), all caused a concentration-dependent increase in the generation of [ 3H]inositol phosphates. The nonhallucinogenic compounds, 6-fluoro- N, N-diethyltryptamine (6-F-DET), lisuride and quipazine, also displayed significant efficacy in stimulating phosphoinositide hydrolysis, while 2-bromo-lysergic acid diethylamide (BOL), which is not a hallucinogen, did not alter inositol phosphate generation. The β-carbolines, harmaline and harmane, also did not alter phosphoinositide hydrolysis. Comparison of these results with previous drug discrimination studies indicated the apparent lack of correlation between the degree of substitution in LSD- and DOM-trained animals and efficacy in stimulating phosphoinositide hydrolysis. The present study indicates that 5-HT 2A-mediated stimulation of phosphoinositide hydrolysis does not appear to be the sole critical signaling mechanism involved in the discriminative effects of hallucinogens.

Evaluation of ODS-AQ stationary phase for use in capillary electrochromatography.

The aim of this study was to evaluate the applicability of ODS-AQ packing material as a stationary phase in capillary electrochromatography (CEC). The electroosmotic flow created on an ODS-AQ stationary phase was measured at different mobile phase compositions and at different column temperatures. It was observed that the electroosmotic flow generated in the column increased by 50% when the temperature of the system was raised from 20 degrees C to 60 degrees C, while all other conditions were kept constant. The electroosmotic flow produced by the ODS-AQ stationary phase was found to be comparable to the flow generated in a column packed with Nucleosil bare-silica material. In addition, a set of polar compounds (D-lysergic acid diethylamide derivatives) was utilized to determine the influence of temperature and mobile phase composition on their chromatographic behavior on an ODS-AQ stationary phase in a CEC mode. A linear relationship between the solute retention factor and column temperatures was seen over the temperature range studied (20 degrees C to 60 degrees C). A quadratic function was used to describe the changes in the solute retention factors with variation of acetonitrile concentration in the mobile phase.