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Siregar P, Audira G, Feng LY, Lee JH, Santoso F, Yu WH, Lai YH, Li JH, Lin YT, Chen JR, Hsiao CD. Pharmaceutical Assessment Suggests Locomotion Hyperactivity in Zebrafish Triggered by Arecoline Might Be Associated with Multiple Muscarinic Acetylcholine Receptors Activation. Toxins (Basel) 2021; 13:toxins13040259. [PMID: 33916832 PMCID: PMC8066688 DOI: 10.3390/toxins13040259] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/21/2021] [Accepted: 04/01/2021] [Indexed: 12/02/2022] Open
Abstract
Arecoline is one of the nicotinic acid-based alkaloids, which is found in the betel nut. In addition to its function as a muscarinic agonist, arecoline exhibits several adverse effects, such as inducing growth retardation and causing developmental defects in animal embryos, including zebrafish, chicken, and mice. In this study, we aimed to study the potential adverse effects of waterborne arecoline exposure on zebrafish larvae locomotor activity and investigate the possible mechanism of the arecoline effects in zebrafish behavior. The zebrafish behavior analysis, together with molecular docking and the antagonist co-exposure experiment using muscarinic acetylcholine receptor antagonists were conducted. Zebrafish larvae aged 96 h post-fertilization (hpf) were exposed to different concentrations (0.001, 0.01, 0.1, and 1 ppm) of arecoline for 30 min and 24 h, respectively, to find out the effect of arecoline in different time exposures. Locomotor activities were measured and quantified at 120 hpf. The results showed that arecoline caused zebrafish larvae locomotor hyperactivities, even at a very low concentration. For the mechanistic study, we conducted a structure-based molecular docking simulation and antagonist co-exposure experiment to explore the potential interactions between arecoline and eight subtypes, namely, M1a, M2a, M2b, M3a, M3b, M4a, M5a, and M5b, of zebrafish endogenous muscarinic acetylcholine receptors (mAChRs). Arecoline was predicted to show a strong binding affinity to most of the subtypes. We also discovered that the locomotion hyperactivity phenotypes triggered by arecoline could be rescued by co-incubating it with M1 to M4 mAChR antagonists. Taken together, by a pharmacological approach, we demonstrated that arecoline functions as a highly potent hyperactivity-stimulating compound in zebrafish that is mediated by multiple muscarinic acetylcholine receptors.
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Affiliation(s)
- Petrus Siregar
- Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taoyuan City 320314, Taiwan; (P.S.); (G.A.)
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, Taoyuan City 3020314, Taiwan;
| | - Gilbert Audira
- Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taoyuan City 320314, Taiwan; (P.S.); (G.A.)
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, Taoyuan City 3020314, Taiwan;
| | - Ling-Yi Feng
- School of Pharmacy and Ph.D. Program in Toxicology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
- Substance and Behavior Addiction Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Jia-Hau Lee
- Department of Biotechnology, College of Life Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (J.-H.L.); (W.-H.Y.)
- Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Fiorency Santoso
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, Taoyuan City 3020314, Taiwan;
| | - Wen-Hao Yu
- Department of Biotechnology, College of Life Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (J.-H.L.); (W.-H.Y.)
| | - Yu-Heng Lai
- Department of Chemistry, Chinese Culture University, Taipei 11114, Taiwan;
| | - Jih-Heng Li
- School of Pharmacy and Ph.D. Program in Toxicology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
- Substance and Behavior Addiction Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Correspondence: (J.-H.L.); (Y.-T.L.); (C.-D.H.)
| | - Ying-Ting Lin
- Department of Biotechnology, College of Life Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (J.-H.L.); (W.-H.Y.)
- Drug Development & Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Correspondence: (J.-H.L.); (Y.-T.L.); (C.-D.H.)
| | - Jung-Ren Chen
- Department of Biological Science & Technology, College of Medicine, I-Shou University, Kaohsiung 82445, Taiwan;
| | - Chung-Der Hsiao
- Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taoyuan City 320314, Taiwan; (P.S.); (G.A.)
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, Taoyuan City 3020314, Taiwan;
- Correspondence: (J.-H.L.); (Y.-T.L.); (C.-D.H.)
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Wooldridge LM, Kangas BD. An assay of drug-induced emesis in the squirrel monkey (Saimiri sciureus). J Med Primatol 2019; 48:236-243. [PMID: 30968960 DOI: 10.1111/jmp.12411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/07/2019] [Accepted: 03/10/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Emesis has significant evolutionary value as a defense mechanism against ingested toxins; however, it is also one of the most common adverse symptoms associated with both disease and medical treatments of disease. The development of improved antiemetic pharmacotherapies has been impeded by a shortage of animal models. METHODS The present studies characterized the responses of the squirrel monkey to pharmacologically diverse emetic drugs. Subjects were administered nicotine (0.032-0.56 mg/kg), lithium chloride (150-250 mg/kg), arecoline (0.01-0.32 mg/kg), or apomorphine (0.032-0.32 mg/kg) and observed for emesis and prodromal hypersalivation. RESULTS Nicotine rapidly produced emesis and hypersalivation. Lithium chloride produced emesis with a longer time course without dose-dependent hypersalivation. Arecoline produced hypersalivation but not emesis. Apomorphine failed to produce emesis or hypersalivation. CONCLUSIONS The squirrel monkey is sensitive to drug-induced emesis by a variety of pharmacological mechanisms and is well-positioned to examine antiemetic efficacy and clinically important side effects of candidate antiemetic pharmacotherapies.
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Affiliation(s)
| | - Brian D Kangas
- Behavioral Biology Program, McLean Hospital, Belmont, Massachusetts.,Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
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Weng JC, Chou YS, Huang GJ, Tyan YS, Ho MC. Mapping brain functional alterations in betel-quid chewers using resting-state fMRI and network analysis. Psychopharmacology (Berl) 2018; 235:1257-1271. [PMID: 29441422 DOI: 10.1007/s00213-018-4841-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 01/21/2018] [Indexed: 02/08/2023]
Abstract
RATIONALE The World Health Organization regards betel quid (BQ) as a human carcinogen, and DSM-IV and ICD-10 dependence symptoms may develop with its heavy use. BQ's possible effects of an enhanced reward system and disrupted inhibitory control may increase the likelihood of habitual substance use. OBJECTIVES The current study aimed to employ resting-state fMRI to examine the hypothesized enhanced reward system (e.g., the basal forebrain system) and disrupted inhibitory control (e.g., the prefrontal system) in BQ chewers. METHODS The current study recruited three groups of 48 male participants: 16 BQ chewers, 15 tobacco- and alcohol-user controls, and 17 healthy controls. We used functional connectivity (FC), mean fractional amplitude of low-frequency fluctuations (mfALFF), and mean regional homogeneity (mReHo) to evaluate functional alternations in BQ chewers. Graph theoretical analysis (GTA) and network-based statistical (NBS) analysis were also performed to identify the functional network differences among the three groups. RESULTS Our hypothesis was partially supported: the enhanced reward system for the BQ chewers (e.g., habitual drug-seeking behavior) was supported; however, their inhibitory control was relatively preserved. In addition, we reported that the BQ chewers may have enhanced visuospatial processing and decreased local segregation. CONCLUSIONS The current results (showing an enhanced reward system in the chewers) provided the clinicians with important insight for the future development of an effective abstinence treatment.
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Affiliation(s)
- Jun-Cheng Weng
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan
- Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan
| | - Yu-Syuan Chou
- Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan
| | - Guo-Joe Huang
- Department of Psychology, Chung Shan Medical University, No. 110, Sec. 1, Chien-Kuo N. Road, Taichung, 402, Taiwan
| | - Yeu-Sheng Tyan
- Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Ming-Chou Ho
- Department of Psychology, Chung Shan Medical University, No. 110, Sec. 1, Chien-Kuo N. Road, Taichung, 402, Taiwan.
- Clinical Psychological Room, Chung Shan Medical University Hospital, Taichung, Taiwan.
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Chiu MC, Shen B, Li SH, Ho MC. Spatial short-term memory is impaired in dependent betel quid chewers. Psychopharmacology (Berl) 2016; 233:2925-32. [PMID: 27236783 DOI: 10.1007/s00213-016-4331-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 05/18/2016] [Indexed: 11/29/2022]
Abstract
RATIONAL Betel quid is regarded as a human carcinogen by the World Health Organization. It remains unknown whether chewing betel quid has a chronic effect on healthy betel quid chewers' memory. OBJECTIVES The present study aims to investigate whether chewing betel quid can affect short-term memory (STM). METHODS Three groups of participants (24 dependent chewers, 24 non-dependent chewers, and 24 non-chewers) were invited to carry out the matrix span task, the object span task, and the digit span task. All span tasks' results were adopted to assess spatial STM, visual STM, and verbal STM, respectively. Besides, there are three set sizes (small, medium, and large) in each span task. RESULTS For the matrix span task, results showed that the dependent chewers had worse performances than the non-dependent chewers and the non-chewers at medium and large set sizes. For the object span task and digit span task, there were no differences in between groups. In each group, recognition performances were worse with the increasing set size and showing successful manipulation of memory load. CONCLUSIONS The current study provided the first evidence that dependent betel quid chewing can selectively impair spatial STM rather than visual STM and verbal STM. Theoretical and practical implications of this result are discussed.
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Affiliation(s)
- Meng-Chun Chiu
- Department of Psychology, Chung-Shan Medical University, No.110, Sec. 1, Chien-Kuo N. Road, Taichung, 402, Taiwan
| | - Bin Shen
- Department of Psychology, Chung-Shan Medical University, No.110, Sec. 1, Chien-Kuo N. Road, Taichung, 402, Taiwan
| | - Shuo-Heng Li
- Department of Psychiatry, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan
| | - Ming-Chou Ho
- Department of Psychology, Chung-Shan Medical University, No.110, Sec. 1, Chien-Kuo N. Road, Taichung, 402, Taiwan. .,Clinical Psychological Room, Chung-Shan Medical University Hospital, Taichung, Taiwan.
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Formulation optimization of arecoline patches. ScientificWorldJournal 2014; 2014:945168. [PMID: 24707220 PMCID: PMC3953398 DOI: 10.1155/2014/945168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 12/01/2013] [Indexed: 12/11/2022] Open
Abstract
The response surface methodology (RSM) including polynomial equations has been used to design an optimal patch formulation with appropriate adhesion and flux. The patch formulations were composed of different polymers, including Eudragit RS 100 (ERS), Eudragit RL 100 (ERL) and polyvinylpyrrolidone K30 (PVP), plasticizers (PEG 400), and drug. In addition, using terpenes as enhancers could increase the flux of the drug. Menthol showed the highest enhancement effect on the flux of arecoline.
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Abstract
Arecoline is one of the major components of betel nuts, which have been consumed as chewing gum in Southeast Asia. In this study, the effects of arecoline on testosterone (T) secretion were explored. Male rats were injected with human chorionic gonadotropin (hCG, 5 IU/kg) or arecoline (1 microg/kg) plus hCG via a jugular catheter. Blood samples were collected at several time intervals subsequent to the challenge. Rat anterior pituitary was treated with gonadotropin-releasing hormone in vitro with or without arecoline, and then the concentrations of luteinizing hormone (LH) in the medium were measured. Rat Leydig cells were purified by Percoll density gradient centrifugation and incubated with arecoline, hCG, forskolin, 8-bromo-cAMP (8-Br-cAMP), nifedipine, nimodipine, or tetrandrine at 34 degrees C for 1 h. A single intravenous injection of arecoline resulted in an increase of the hCG-induced level of plasma T. Administration of arecoline (10(-8) to 10(-6) M) in vitro increased T production in Leydig cells. The stimulatory effect of arecoline on T release in vitro was enhanced by hCG (0.001 IU/ml), forskolin (10(-6) M), or 8-Br-cAMP (10(-5) M). By contrast, nifedipine, nimodipine, or tetrandrine inhibited the increased T concentrations induced by arecoline. Western blot showed that arecoline increases steroidogenic acute regulatory (StAR) protein expression compared with vehicle. These results suggested that arecoline stimulates testosterone production by acting directly on Leydig cells via mechanisms involving an activation of L-type calcium channels, increasing the activity of 17beta-hydroxysteroid dehydrogenase and enhancing the expression of StAR.
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Affiliation(s)
- Shyi-Wu Wang
- Department of Physiology, School of Medicine, Chang Gung University, Kweisan, Taoyuan, Taiwan, ROC.
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Plate R, Jans CGJM, Plaum MJM, de Boer T. Synthesis and in vitro muscarinic activities of a series of 1,3-diazacycloalkyl carboxaldehyde oxime derivatives. Bioorg Med Chem 2002; 10:1143-52. [PMID: 11836126 DOI: 10.1016/s0968-0896(01)00379-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A series of 1,3-diazacycloalkyl carboxaldehyde oxime derivatives was synthesized and tested for muscarinic activity in receptor binding assays using [3H]-oxotremorine-M (OXO-M) and [3H]-pirenzepine (PZ) as ligands. Potential muscarinic agonistic or antagonistic properties of the compounds were determined using binding studies measuring their potencies to inhibit the binding of OXO-M and PZ. Preferential inhibition of OXO-M binding was used as an indicator for potential muscarinic agonistic properties; this potential was confirmed in functional studies on isolated organs.
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Affiliation(s)
- Ralf Plate
- Department of Medicinal Chemistry, N.V. Organon, PO Box 20, 5340 BH, Oss, The Netherlands.
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Plate R, Plaum MJ, van der Hulst RG, de Boer T. Synthesis and in vitro muscarinic activities of a series of 3-(pyrazol-3-yl)-1-azabicyclo[2.2.2]octanes. Bioorg Med Chem 2000; 8:449-54. [PMID: 10722168 DOI: 10.1016/s0968-0896(99)00299-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A series of 3-(pyrazol-3-yl)-1-azabicyclo[2.2.2]octane derivatives C (Fig. 1) was synthesized and tested for muscarinic activity in receptor binding assays using [3H]-oxotremorine-M (OXO-M) and [3H]-pirenzepine (PZ) as ligands. Potential muscarinic agonistic or antagonistic properties of the compounds were determined using binding studies measuring their potencies to inhibit the binding of OXO-M and PZ. Preferential inhibition of OXO-M binding was used as an indicator for potential muscarinic agonistic properties; this potential was confirmed in functional studies on isolated organs.
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Affiliation(s)
- R Plate
- Department of Medicinal Chemistry, N. V. Organon, Oss, The Netherlands.
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Buccafusco JJ, Zhang LC, Shuster LC, Jonnala RR, Gattu M. Prevention of precipitated withdrawal symptoms by activating central cholinergic systems during a dependence-producing schedule of morphine in rats. Brain Res 2000; 852:76-83. [PMID: 10661498 DOI: 10.1016/s0006-8993(99)02197-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Previous studies in this and other laboratories have suggested an important role for central cholinergic neurons in the expression of morphine withdrawal symptoms. This study was designed to determine whether the symptoms of withdrawal could be mitigated by normalization of the effect of morphine on cholinergic neurons. Since this effect is generally inhibitory, we used centrally acting cholinergic agonists to augment central cholinergic tone during chronic morphine infusion. Rats were made dependent following the intra-arterial (i.a.) infusion of increasing concentrations (35-100 mg kg(-1) day(-1)) of morphine over 5 days. I.a. injection of 0.5 mg/kg of naloxone precipitated a profound withdrawal response that included a dramatic increase in mean arterial pressure (MAP) which was maintained over the 60-min observation period, a short duration increase in heart rate (HR), and characteristic opiate withdrawal symptoms. In separate groups of rats, non-toxic doses (50 and 250 microg/kg) of the acetylcholinesterase (AChE) inhibitor, diisopropylflurophosphate (DFP) were administered as single daily injections concomitant with the morphine infusion. DFP treated rats, exhibited significantly reduced expression of the naloxone-evoked pressor response. The apparent anti-withdrawal effect of DFP was not reproduced by the selective peripherally acting AChE inhibitor, echothiophate, although both compounds effectively reduced the expression of certain other withdrawal symptoms. The centrally acting muscarinic cholinergic receptor agonist, arecoline, resulted in an even more impressive suppression of withdrawal symptoms. While not all symptoms associated with morphine withdrawal are mediated via central cholinergic pathways, these results suggest that physical dependence on morphine can be suppressed to a significant degree by the augmentation of central cholinergic activity during morphine administration.
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Affiliation(s)
- J J Buccafusco
- Alzheimer's Research Center, Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta 30912-2300, USA.
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Dukoff R, Wilkinson CW, Lasser R, Friz J, Conway A, Bahro M, Peskind ER, Sunderland T. Physostigmine challenge before and after chronic cholinergic blockade in elderly volunteers. Biol Psychiatry 1999; 46:189-95. [PMID: 10418693 DOI: 10.1016/s0006-3223(98)00286-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND As a test of possible muscarinic up-regulation, the cortisol response to intravenous (i.v.) physostigmine (an anticholinesterase) was measured in 9 elderly volunteers before and after chronic cholinergic blockade with the muscarinic cholinergic antagonist scopolamine. METHODS Each of the 9 elderly control subjects was given two physostigmine (0.5 mg i.v.) infusions separated by 21 doses of nightly scopolamine (1.2 mg p.o.). No scopolamine was administered the night before infusions, and glycopyrrolate (0.2 mg i.v.) was administered prior to physostigmine, to block its peripheral effects. Vital signs were monitored and blood samples were collected at six time points surrounding the physostigmine infusion (-10, +10, +20, +30, +50, and +70 min). Behavioral measures and cognitive tests were administered prior to and 30 min after the physostigmine. RESULTS The cortisol response to physostigmine was greater after the second (post-chronic scopolamine) infusion study compared to the first (p < .05) as measured by an area under the curve analysis of all time points. When individual time points were compared, the mean cortisol response was significantly increased after the second physostigmine infusion at the +50- and +70-min time points (p < .05). There were no significant changes in behavioral rating scales, cognitive tests, or vital signs between the two physostigmine infusion study days. CONCLUSIONS This study demonstrates increased hypothalamic-pituitary-adrenocortical axis responsivity to a central nervous system cholinergic stimulus after chronic muscarinic blockade in 9 elderly control subjects. It also gives further evidence to support previous suggestions of muscarinic plasticity, specifically postsynaptic up-regulation, in the aging brain following exposure to chronic anticholinergic treatment.
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Affiliation(s)
- R Dukoff
- Geriatric Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland, USA
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Plate R, Plaum MJ, Pintar P, Jans CG, de Boer T, Dijcks FA, Ruigt G, Andrews JS. Synthesis, and in vitro and in vivo muscarinic pharmacological properties of a series of 1,6-dihydro-5-(4H)-pyrimidinone oximes. Bioorg Med Chem 1998; 6:1404-20. [PMID: 9801812 DOI: 10.1016/s0968-0896(98)00074-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A series of 1,6-dihydro-5-(4H)-pyrimidinone oxime derivatives I was synthesized (Scheme 1, Tables 1 and 2) and tested for muscarinic activity (Table 3) in receptor binding assays using [3H]-oxotremorine-M (Oxo-M) and [3H]-pirenzepine (Pz) as ligands. Potential muscarinic agonistic or antagonistic properties of the compounds were determined using binding studies that measured their potencies to inhibit the binding of Oxo-M and Pz. Preferential inhibition of Oxo-M binding was used as an indicator for potential muscarinic agonistic properties; this potential was confirmed in functional studies on isolated organs. The series produced a wide range of active compounds with differing degrees of selectivity in M1, M2, and M3 functional models. Several compounds that have mixed agonist/antagonist profiles were able to reduce cholinergic-related cognitive impairments in models of mnemonic function. Substitutions (I, e.g. R2 or R3 = Me) at the 1,6-dihydro-5-(4H)pyrimidine ring disrupted binding and efficacy, whereas systematic variation of the oximes substituent R1 resulted in various degrees of potency and selectivity dependent on the nature of the substitution.
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Affiliation(s)
- R Plate
- Department of Medicinal Chemistry, N. V. Organon, Oss, The Netherlands
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Asthana S, Greig NH, Holloway HW, Raffaele KC, Berardi A, Schapiro MB, Rapoport SI, Soncrant TT. Clinical pharmacokinetics of arecoline in subjects with Alzheimer's disease. Clin Pharmacol Ther 1996; 60:276-82. [PMID: 8841150 DOI: 10.1016/s0009-9236(96)90054-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To study the pharmacokinetics and pharmacodynamics of intravenously administered arecoline in subjects with Alzheimer's disease. METHODS Plasma arecoline concentrations were measured during and after high-dose (i.e., 5 mg intravenously over 30 minutes) and up to 2 weeks of continuous multiple-dose steady-state intravenous infusions of arecoline in 15 subjects with mild to moderate Alzheimer's disease. During multiple-dose infusions, the dose of arecoline was escalated from 0.5 to 40 mg/day. Psychometric tests were administered at baseline and every other dose to determine an "optimal dose" for each subject. This dose then was administered for 1 week using a randomized, placebo-controlled, double blind, crossover design. Plasma drug concentrations were measured by GC-MS. RESULTS The optimal dose of arecoline varied fourfold across subjects (4 mg/day, n = 6; 16 mg/day, n = 3) with mean plasma half-lives of 0.95 +/- 0.54 and 9.3 +/- 4.5 (SD) minutes. Clearance and volume of distribution were 13.6 +/- 5.8 L/min and 205 +/- 170 (SD) L, respectively. At the dose that optimized memory, the mean plasma level was 0.31 +/- 0.14 (SD) ng/ml, and it predicted the optimal dose in all subjects. CONCLUSIONS Because optimal dose variation is due to differing plasma kinetics, the plasma arecoline level measured at a single infusion rate can be used to choose the optimal dose for memory enhancement in patients with Alzheimer's disease.
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Affiliation(s)
- S Asthana
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, USA
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