Carl-Magnus A. Andersson

Bio: Carl-Magnus A. Andersson is an academic researcher from ACADIA Pharmaceuticals Inc.. The author has contributed to research in topics: Inverse agonist & Receptor. The author has an hindex of 7, co-authored 14 publications receiving 523 citations. Previous affiliations of Carl-Magnus A. Andersson include University of Calgary.

5-Hydroxytryptamine2A Receptor Inverse Agonists as Antipsychotics

Abstract: We have used a cell-based functional assay to define the pharmacological profiles of a wide range of central nervous system active compounds as agonists, competitive antagonists, and inverse agonists at almost all known monoaminergic G-protein-coupled receptor (GPCR) subtypes. Detailed profiling of 40 antipsychotics confirmed that as expected, most of these agents are potent competitive antagonists of the dopamine D2 receptor. Surprisingly, this analysis also revealed that most are potent and fully efficacious 5-hydroxytryptamine (5-HT)2A receptor inverse agonists. No other molecular property was shared as universally by this class of compounds. Furthermore, comparisons of receptor potencies revealed that antipsychotics with the highest extrapyramidal side effects (EPS) liability are significantly more potent at D2 receptors, the EPS-sparing atypical agents had relatively higher potencies at 5-HT2A receptors, while three were significantly more potent at 5-HT2A receptors. Functional high-throughput screening of a diverse chemical library identified 530 ligands with inverse agonist activity at 5-HT2A receptors, including several series of compounds related to known antipsychotics, as well as a number of novel chemistries. An analog of one of the novel chemical series, AC-90179, was pharmacologically profiled against the remaining monoaminergic GPCRs and found to be a highly selective 5-HT2A receptor inverse agonist. The behavioral pharmacology of AC-90179 is characteristic of an atypical antipsychotic agent.

Pharmacological and Behavioral Profile of N-(4-Fluorophenylmethyl)-N-(1-methylpiperidin-4-yl)-N′-(4-(2-methylpropyloxy)phenylmethyl) Carbamide (2R,3R)-Dihydroxybutanedioate (2:1) (ACP-103), a Novel 5-Hydroxytryptamine2A Receptor Inverse Agonist

Abstract: The in vitro and in vivo pharmacological properties of N -(4-fluorophenylmethyl)- N -(1-methylpiperidin-4-yl)- N ′-(4-(2-methylpropyloxy)phenylmethyl)carbamide (2 R ,3 R )-dihydroxybutanedioate (2:1) (ACP-103) are presented. A potent 5-hydroxytryptamine (5-HT)2A receptor inverse agonist ACP-103 competitively antagonized the binding of [3H]ketanserin to heterologously expressed human 5-HT2A receptors with a mean p K i of 9.3 in membranes and 9.70 in whole cells. ACP-103 displayed potent inverse agonist activity in the cell-based functional assay receptor selection and amplification technology (R-SAT), with a mean pIC50 of 8.7. ACP-103 demonstrated lesser affinity (mean p K i of 8.80 in membranes and 8.00 in whole cells, as determined by radioligand binding) and potency as an inverse agonist (mean pIC50 7.1 in R-SAT) at human 5-HT2C receptors, and lacked affinity and functional activity at 5-HT2B receptors, dopamine D2 receptors, and other human monoaminergic receptors. Behaviorally, ACP-103 attenuated head-twitch behavior (3 mg/kg p.o.), and prepulse inhibition deficits (1-10 mg/kg s.c.) induced by the 5-HT2A receptor agonist (±)-2,5-dimethoxy-4-iodoamphetamine hydrochloride in rats and reduced the hyperactivity induced in mice by the N -methyl-d-aspartate receptor noncompetitive antagonist 5 H -dibenzo[ a , d ]cyclohepten-5,10-imine (dizocilpine maleate; MK-801) (0.1 and 0.3 mg/kg s.c.; 3 mg/kg p.o.), consistent with a 5-HT2A receptor mechanism of action in vivo and antipsychotic-like efficacy. ACP-103 demonstrated >42.6% oral bioavailability in rats. Thus, ACP-103 is a potent, efficacious, orally active 5-HT2A receptor inverse agonist with a behavioral pharmacological profile consistent with utility as an antipsychotic agent.

Selective serotonin 2A/2C receptor inverse agonists as therapeutics for neurodegenerative diseases

Abstract: Behavioral pharmacological data with the compound of formula (I), a novel and selective 5HT2A/2C receptor inverse agonist, demonstrate in vivo efficacy in models of psychosis and dyskinesias. This includes activity in reversing MK-801 induced locomotor behaviors, suggesting that this compound may be an efficacious anti-psychotic, and activity in an MPTP primate model of dyskinesias, suggesting efficacy as an anti-dyskinesia agent. These data support the hypothesis that 5HT2A/2C receptor inverse agonism may confer antipsychotic and anti-dyskinetic efficacy in humans, and indicate a use of the compound of formula (I) and related agents as novel therapeutics for Parkinson's Disease, related human neurodegenerative diseases, and psychosis.

Pharmacological Characterization of AC-90179 [2-(4-Methoxyphenyl)-N-(4-methyl-benzyl)-N-(1-methyl-piperidin-4-yl)-acetamide Hydrochloride]: A Selective Serotonin 2A Receptor Inverse Agonist

Abstract: The primary purpose of the present series of experiments was to characterize the in vitro and in vivo pharmacology profile of 2-(4-methoxy-phenyl)-N-(4-methyl-benzyl)-N-(1-methyl-piperidin-4-yl)-acetamide hydrochloride (AC-90179), a selective serotonin (5-HT2A) receptor inverse agonist, in comparison with the antipsychotics haloperidol and clozapine. The secondary purpose was to characterize the pharmacokinetic profile of AC-90179. Like all atypical antipsychotics, AC-90179 shows high potency as an inverse agonist and competitive antagonist at 5HT2A receptors. In addition, AC-90179 exhibits antagonism at 5HT2C receptors. In contrast, AC-90179 does not have significant potency for D2 and H1 receptors that have been implicated in the dose-limiting side effects of other antipsychotic drugs. The ability of AC-90179 to block 5-HT2A receptor signaling in vivo was demonstrated by its blockade of the rate-decreasing effects of the 5-HT2A agonist, (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride, under a fixed ratio schedule of reinforcement. Similar to clozapine and haloperidol, AC-90179 attenuated phencyclidine-induced hyperactivity. Although haloperidol impaired acquisition of a simple autoshaped response and induced cataleptic-like effects at behaviorally efficacious doses, AC-90179 and clozapine did not. Furthermore, unlike haloperidol and clozapine, AC-90179 did not decrease spontaneous locomotor behavior at efficacious doses. Limited oral bioavailability of AC-90179 likely reflects rapid metabolism rather than poor absorption. Taken together, a compound with a similar pharmacological profile as AC-90179 and with increased oral bioavailability may have potential for the treatment of psychosis.

Atypical Antipsychotics: Mechanism of Action:

Abstract: Background:Al though the prin ci pal brain tar get that all an tipsy chotic drugs at tach to is the do pamine D2 re cep tor, tra di tional or typi cal an tipsy chot ics, by at tach ing to it, in duce ex tra py r a mi dal signs and symp toms (EPS). They also, by bind ing to the D2 re cep tor, ele vate se rum pro lac tin. Atypi cal a ntipsy chot ics given in dos ages within the clini cally ef fec tive range do not bring about these adverse clini cal ef fects. To un der stand how these drugs work, it is im por tant to ex am ine the atypical an tipsychot ics' mecha nism of ac tion and how it dif fers from that of the more typi cal drugs.Method:This re view analy zes the af fini ties, the oc cu pan cies, and the dis so cia tion time- course of vari ous an tipsy chot ics at do pa mine D2 re cep tors and at se ro tonin (5-HT) re cep tors, both in the test tube and in live pa tients.Results:Of the 31 an tipsy chot ics ex am ined, the older tra di tional an tipsy chot ics such as tri fluperazine, pi mozide, chlor ...

Atypical Antipsychotics: Mechanism of Action

Abstract: Background: Although the principal brain target that all antipsychotic drugs attach to is the dopamine D2 receptor, traditional or typical antipsychotics, by attaching to it, induce extrapyramidal signs and symptoms (EPS). They also, by binding to the D2 receptor, elevate serum prolactin. Atypical antipsychotics given in dosages within the clinically effective range do not bring about these adverse clinical effects. To understand how these drugs work, it is important to examine the atypical antipsychotics’ mechanism of action and how it differs from that of the more typical drugs. Method: This review analyzes the affinities, the occupancies, and the dissociation time-course of various antipsychotics at dopamine D2 receptors and at serotonin (5-HT) receptors, both in the test tube and in live patients. Results: Of the 31 antipsychotics examined, the older traditional antipsychotics such as trifluperazine, pimozide, chlorpromazine, fluphenazine, haloperidol, and flupenthixol bind more tightly than dopamine ...

Constitutive activity of G-protein-coupled receptors: cause of disease and common property of wild-type receptors

Abstract: The aim of this review is to provide a systematic overview on constitutively active G-protein-coupled receptors (GPCRs), a rapidly evolving area in signal transduction research. We will discuss mechanisms, pharmacological tools and methodological approaches to analyze constitutive activity. The two-state model defines constitutive activity as the ability of a GPCR to undergo agonist-independent isomerization from an inactive (R) state to an active (R*) state. While the two-state model explains basic concepts of constitutive GPCR activity and inverse agonism, there is increasing evidence for multiple active GPCR conformations with distinct biological activities. As a result of constitutive GPCR activity, basal G-protein activity increases. Until now, constitutive activity has been observed for more than 60 wild-type GPCRs from the families 1–3 and from different species including humans and commonly used laboratory animal species. Additionally, several naturally occurring and disease-causing GPCR mutants with increased constitutive activity relative to wild-type GPCRs have been identified. Alternative splicing, RNA editing, polymorphisms within a given species, species variants and coupling to specific G-proteins all modulate the constitutive activity of GPCRs, providing multiple regulatory switches to fine-tune basal cellular activities. The most important pharmacological tools to analyze constitutive activity are inverse agonists and Na+ that stabilize the R state, and pertussis toxin that uncouples GPCRs from Gi/Go-proteins. Constitutive activity is observed at low and high GPCR expression levels, in native systems and in recombinant systems, and has been reported for GPCRs coupled to Gs-, Gi- and Gq-proteins. Constitutive activity of neurotransmitter GPCRs may provide a tonic support for basal neuronal activity. For the majority of GPCRs known to be constitutively active, inverse agonists have already been identified. Inverse agonists may be useful in the treatment of neuropsychiatric and cardiovascular diseases and of diseases caused by constitutively active GPCR mutants.