1
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Li R, Li Z, Wu N, Tan B. Effect of pre‐treatment on the functional properties of germinated whole grains: A review. Cereal Chem 2021. [DOI: 10.1002/cche.10500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ren Li
- Academy of National Food and Strategic Reserves Administration Beijing China
- Department of Food and Engineering College of Food Heilongjiang Bayi Agricultural University Heilongjiang, Daqing China
| | - Zhi‐Jiang Li
- Department of Food and Engineering College of Food Heilongjiang Bayi Agricultural University Heilongjiang, Daqing China
| | - Na‐Na Wu
- Academy of National Food and Strategic Reserves Administration Beijing China
| | - Bin Tan
- Academy of National Food and Strategic Reserves Administration Beijing China
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Jayakar SS, Chiara DC, Zhou X, Wu B, Bruzik KS, Miller KW, Cohen JB. Photoaffinity labeling identifies an intersubunit steroid-binding site in heteromeric GABA type A (GABA A) receptors. J Biol Chem 2020; 295:11495-11512. [PMID: 32540960 DOI: 10.1074/jbc.ra120.013452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/09/2020] [Indexed: 12/11/2022] Open
Abstract
Allopregnanolone (3α5α-P), pregnanolone, and their synthetic derivatives are potent positive allosteric modulators (PAMs) of GABAA receptors (GABAARs) with in vivo anesthetic, anxiolytic, and anti-convulsant effects. Mutational analysis, photoaffinity labeling, and structural studies have provided evidence for intersubunit and intrasubunit steroid-binding sites in the GABAAR transmembrane domain, but revealed only little definition of their binding properties. Here, we identified steroid-binding sites in purified human α1β3 and α1β3γ2 GABAARs by photoaffinity labeling with [3H]21-[4-(3-(trifluoromethyl)-3H-diazirine-3-yl)benzoxy]allopregnanolone ([3H]21-pTFDBzox-AP), a potent GABAAR PAM. Protein microsequencing established 3α5α-P inhibitable photolabeling of amino acids near the cytoplasmic end of the β subunit M4 (β3Pro-415, β3Leu-417, and β3Thr-418) and M3 (β3Arg-309) helices located at the base of a pocket in the β+-α- subunit interface that extends to the level of αGln-242, a steroid sensitivity determinant in the αM1 helix. Competition photolabeling established that this site binds with high affinity a structurally diverse group of 3α-OH steroids that act as anesthetics, anti-epileptics, and anti-depressants. The presence of a 3α-OH was crucial: 3-acetylated, 3-deoxy, and 3-oxo analogs of 3α5α-P, as well as 3β-OH analogs that are GABAAR antagonists, bound with at least 1000-fold lower affinity than 3α5α-P. Similarly, for GABAAR PAMs with the C-20 carbonyl of 3α5α-P or pregnanolone reduced to a hydroxyl, binding affinity is reduced by 1,000-fold, whereas binding is retained after deoxygenation at the C-20 position. These results provide a first insight into the structure-activity relationship at the GABAAR β+-α- subunit interface steroid-binding site and identify several steroid PAMs that act via other sites.
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Affiliation(s)
- Selwyn S Jayakar
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
| | - David C Chiara
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
| | - Xiaojuan Zhou
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Bo Wu
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois
| | - Karol S Bruzik
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois
| | - Keith W Miller
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Jonathan B Cohen
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
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3
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Belelli D, Hogenkamp D, Gee KW, Lambert JJ. Realising the therapeutic potential of neuroactive steroid modulators of the GABA A receptor. Neurobiol Stress 2019; 12:100207. [PMID: 32435660 PMCID: PMC7231973 DOI: 10.1016/j.ynstr.2019.100207] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 12/19/2019] [Indexed: 01/27/2023] Open
Abstract
In the 1980s particular endogenous metabolites of progesterone and of deoxycorticosterone were revealed to be potent, efficacious, positive allosteric modulators (PAMs) of the GABAA receptor (GABAAR). These reports were followed by the discovery that such steroids may be synthesised not only in peripheral endocrine glands, but locally in the central nervous system (CNS), to potentially act as paracrine, or autocrine "neurosteroid" messengers, thereby fine tuning neuronal inhibition. These discoveries triggered enthusiasm to elucidate the physiological role of such neurosteroids and explore whether their levels may be perturbed in particular psychiatric and neurological disorders. In preclinical studies the GABAAR-active steroids were shown to exhibit anxiolytic, anticonvulsant, analgesic and sedative properties and at relatively high doses to induce a state of general anaesthesia. Collectively, these findings encouraged efforts to investigate the therapeutic potential of neurosteroids and related synthetic analogues. However, following over 30 years of investigation, realising their possible medical potential has proved challenging. The recent FDA approval for the natural neurosteroid allopregnanolone (brexanolone) to treat postpartum depression (PPD) should trigger renewed enthusiasm for neurosteroid research. Here we focus on the influence of neuroactive steroids on GABA-ergic signalling and on the challenges faced in developing such steroids as anaesthetics, sedatives, analgesics, anticonvulsants, antidepressants and as treatments for neurodegenerative disorders.
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Affiliation(s)
- Delia Belelli
- Systems Medicine, Neuroscience, Mail Box 6, University of Dundee, Ninewells Hospital and Medical School, Dundee, DD1 9SY, United Kingdom
| | - Derk Hogenkamp
- Department of Pharmacology, 110C Med Surge1, Mail Code 4625, University of California, Irvine, School of Medicine, Irvine, CA, 92697, USA
| | - Kelvin W Gee
- Department of Pharmacology, 110C Med Surge1, Mail Code 4625, University of California, Irvine, School of Medicine, Irvine, CA, 92697, USA
| | - Jeremy J Lambert
- Systems Medicine, Neuroscience, Mail Box 6, University of Dundee, Ninewells Hospital and Medical School, Dundee, DD1 9SY, United Kingdom
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4
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Effects of cyclic cellulase conditioning and germination treatment on the γ-aminobutyric acid content and the cooking and taste qualities of germinated brown rice. Food Chem 2019; 289:232-239. [DOI: 10.1016/j.foodchem.2019.03.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 03/07/2019] [Accepted: 03/09/2019] [Indexed: 01/25/2023]
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5
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Lau C, Thakre PP, Bellingham MC. Alfaxalone Causes Reduction of Glycinergic IPSCs, but Not Glutamatergic EPSCs, and Activates a Depolarizing Current in Rat Hypoglossal Motor Neurons. Front Cell Neurosci 2019; 13:100. [PMID: 30967762 PMCID: PMC6440435 DOI: 10.3389/fncel.2019.00100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 02/27/2019] [Indexed: 11/20/2022] Open
Abstract
We investigated effects of the neuroactive steroid anesthetic alfaxalone on intrinsic excitability, and on inhibitory and excitatory synaptic transmission to hypoglossal motor neurons (HMNs). Whole cell recordings were made from HMNs in brainstem slices from 7 to 14-day-old Wistar rats. Spontaneous, miniature, and evoked inhibitory post-synaptic currents (IPSCs), and spontaneous and evoked excitatory PSCs (EPSCs) were recorded at –60 mV. Alfaxalone did not alter spontaneous glycinergic IPSC peak amplitude, rise-time or half-width up to 10 μM, but reduced IPSC frequency from 3 μM. Evoked IPSC amplitude was reduced from 30 nM. Evoked IPSC rise-time was prolonged and evoked IPSC decay time was increased only by 10 μM alfaxalone. Alfaxalone also decreased evoked IPSC paired pulse ratio (PPR). Spontaneous glutamatergic EPSC amplitude and frequency were not altered by alfaxalone, and evoked EPSC amplitude and PPR was also unchanged. Alfaxalone did not alter HMN repetitive firing or action potential amplitude. Baseline holding current at −60 mV with a CsCl-based pipette solution was increased in an inward direction; this effect was not seen when tetrodotoxin (TTX) was present. These results suggest that alfaxalone modulates glycine receptors (GlyRs), causing a delayed and prolonged channel opening, as well as causing presynaptic reduction of glycine release, and activates a membrane current, which remains to be identified. Alfaxalone selectively reduces glycinergic inhibitory transmission to rat HMNs via a combination of pre- and post-synaptic mechanisms. The net effect of these responses to alfaxalone is to increase HMN excitability and may therefore underlie neuro-motor excitation during neurosteroid anesthesia.
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Affiliation(s)
- Cora Lau
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Prajwal P Thakre
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Mark C Bellingham
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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6
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Wei Y, Qiu G, Lei B, Qin L, Chu H, Lu Y, Zhu G, Gao Q, Huang Q, Qian G, Liao P, Luo X, Zhang X, Zhang C, Li Y, Zheng S, Yu Y, Tang P, Ni J, Yan P, Zhou Y, Li P, Huang X, Gong A, Liu J. Oral Delivery of Propofol with Methoxymethylphosphonic Acid as the Delivery Vehicle. J Med Chem 2017; 60:8580-8590. [DOI: 10.1021/acs.jmedchem.7b01133] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Yonggang Wei
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Guanpeng Qiu
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Bailin Lei
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Linlin Qin
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Hongzhu Chu
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Yonghua Lu
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Guozhi Zhu
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Qiu Gao
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Qingping Huang
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Guofei Qian
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Pengfei Liao
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Xinfeng Luo
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Xiaowei Zhang
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Chen Zhang
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Yao Li
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Suxin Zheng
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Yan Yu
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Pingming Tang
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Jia Ni
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Pangke Yan
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Yi Zhou
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Pan Li
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Xia Huang
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Aisheng Gong
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
| | - Jianyu Liu
- Haisco Pharmaceuticals Group Co. Ltd., 136 Baili Road,
Wenjiang District, Chengdu, 611130, China
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7
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Qin L, Ren L, Wan S, Liu G, Luo X, Liu Z, Li F, Yu Y, Liu J, Wei Y. Design, Synthesis, and Evaluation of Novel 2,6-Disubstituted Phenol Derivatives as General Anesthetics. J Med Chem 2017; 60:3606-3617. [DOI: 10.1021/acs.jmedchem.7b00254] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Linlin Qin
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Lei Ren
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Songlin Wan
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Guoliang Liu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Xinfeng Luo
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Zhenhong Liu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Fangqiong Li
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Yan Yu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Jianyu Liu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Yonggang Wei
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
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8
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Zhang C, Li F, Yu Y, Huang A, He P, Lei M, Wang J, Huang L, Liu Z, Liu J, Wei Y. Design, Synthesis, and Evaluation of a Series of Novel Benzocyclobutene Derivatives as General Anesthetics. J Med Chem 2017; 60:3618-3625. [PMID: 28430431 DOI: 10.1021/acs.jmedchem.7b00253] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Chen Zhang
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Fangqiong Li
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Yan Yu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Anbang Huang
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Ping He
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Ming Lei
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Jianmin Wang
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Longbin Huang
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Zhenhong Liu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Jianyu Liu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Yonggang Wei
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
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9
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Carver CM, Reddy DS. Neurosteroid Structure-Activity Relationships for Functional Activation of Extrasynaptic δGABA(A) Receptors. J Pharmacol Exp Ther 2016; 357:188-204. [PMID: 26857959 DOI: 10.1124/jpet.115.229302] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 02/05/2016] [Indexed: 01/18/2023] Open
Abstract
Synaptic GABAA receptors are primary mediators of rapid inhibition in the brain and play a key role in the pathophysiology of epilepsy and other neurologic disorders. The δ-subunit GABAA receptors are expressed extrasynaptically in the dentate gyrus and contribute to tonic inhibition, promoting network shunting as well as reducing seizure susceptibility. However, the neurosteroid structure-function relationship at δGABA(A) receptors within the native hippocampus neurons remains unclear. Here we report a structure-activity relationship for neurosteroid modulation of extrasynaptic GABAA receptor-mediated tonic inhibition in the murine dentate gyrus granule cells. We recorded neurosteroid allosteric potentiation of GABA as well as direct activation of tonic currents using a wide array of natural and synthetic neurosteroids. Our results shows that, for all neurosteroids, the C3α-OH group remains obligatory for extrasynaptic receptor functional activity, as C3β-OH epimers were inactive in activating tonic currents. Allopregnanolone and related pregnane analogs exhibited the highest potency and maximal efficacy in promoting tonic currents. Alterations at the C17 or C20 region of the neurosteroid molecule drastically altered the transduction kinetics of tonic current activation. The androstane analogs had the weakest modulatory response among the analogs tested. Neurosteroid potentiation of tonic currents was completely (approximately 95%) diminished in granule cells from δ-knockout mice, suggesting that δ-subunit receptors are essential for neurosteroid activity. The neurosteroid sensitivity of δGABA(A) receptors was confirmed at the systems level using a 6-Hz seizure test. A consensus neurosteroid pharmacophore model at extrasynaptic δGABA(A) receptors is proposed based on a structure-activity relationship for activation of tonic current and seizure protection.
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Affiliation(s)
- Chase Matthew Carver
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas
| | - Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas
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10
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Study on the optimal moisture adding rate of brown rice during germination by using segmented moisture conditioning method. Journal of Food Science and Technology 2015; 52:6599-606. [PMID: 26396406 DOI: 10.1007/s13197-015-1722-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 07/02/2014] [Accepted: 01/07/2015] [Indexed: 10/24/2022]
Abstract
The aim of this study was to find out the optimal moisture adding rate of brown rice during the process of germination. The process of water addition in brown rice could be divided into three stages according to different water absorption speeds in soaking process. Water was added with three different speeds in three stages to get the optimal water adding rate in the whole process of germination. Thus, the technology of segmented moisture conditioning which is a method of adding water gradually was put forward. Germinated brown rice was produced by using segmented moisture conditioning method to reduce the loss of water-soluble nutrients and was beneficial to the accumulation of gamma aminobutyric acid. The effects of once moisture adding amount in three stages on the gamma aminobutyric acid content in germinated brown rice and germination rate of brown rice were investigated by using response surface methodology. The optimum process parameters were obtained as follows: once moisture adding amount of stage I with 1.06 %/h, once moisture adding amount of stage II with 1.42 %/h and once moisture adding amount of stage III with 1.31 %/h. The germination rate under the optimum parameters was 91.33 %, which was 7.45 % higher than that of germinated brown rice produced by soaking method (84.97 %). The content of gamma aminobutyric acid in germinated brown rice under the optimum parameters was 29.03 mg/100 g, which was more than two times higher than that of germinated brown rice produced by soaking method (12.81 mg/100 g). The technology of segmented moisture conditioning has potential applications for studying many other cereals.
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11
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Thirupathi B, Srinivas R, Prasad AN, Kumar JKP, Reddy BM. Green Progression for Synthesis of Regioselective β-Amino Alcohols and Chemoselective Alkylated Indoles. Org Process Res Dev 2010. [DOI: 10.1021/op1002177] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Boningari Thirupathi
- Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Uppal Road, Hyderabad - 500 607, India
| | - Rapelli Srinivas
- Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Uppal Road, Hyderabad - 500 607, India
| | - Avvari N. Prasad
- Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Uppal Road, Hyderabad - 500 607, India
| | - J. K. Prashanth Kumar
- Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Uppal Road, Hyderabad - 500 607, India
| | - Benjaram M. Reddy
- Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Uppal Road, Hyderabad - 500 607, India
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12
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Ke X, Hu H, Zhang K, Xu W, Zhu Q, Wu L, Hu X. Significant steroids: effective and general synthesis of 4α- and 4β-amino-5α-androstanes. Chem Commun (Camb) 2009:1037-9. [DOI: 10.1039/b817910g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Rudolph U, Antkowiak B. Molecular and neuronal substrates for general anaesthetics. Nat Rev Neurosci 2004; 5:709-20. [PMID: 15322529 DOI: 10.1038/nrn1496] [Citation(s) in RCA: 515] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although general anaesthesia has been of tremendous importance for the development of surgery, the underlying mechanisms by which this state is achieved are only just beginning to be understood in detail. In this review, we describe the neuronal systems that are thought to be involved in mediating clinically relevant actions of general anaesthetics, and we go on to discuss how the function of individual drug targets, in particular GABA(A)-receptor subtypes, can be revealed by genetic studies in vivo.
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Affiliation(s)
- Uwe Rudolph
- Institute of Pharmacology and Toxicology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
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14
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Weir CJ, Ling ATY, Belelli D, Wildsmith JAW, Peters JA, Lambert JJ. The interaction of anaesthetic steroids with recombinant glycine and GABAA receptors. Br J Anaesth 2004; 92:704-11. [PMID: 15033889 DOI: 10.1093/bja/aeh125] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Anaesthetic steroids are established positive allosteric modulators of GABAA receptors, but little is known concerning steroid modulation of strychnine-sensitive glycine receptors, the principal mediators of fast, inhibitory neurotransmission in the brain stem and spinal cord. This study compared the modulatory actions of five anaesthetic pregnane steroids and two non-anaesthetic isomers at human recombinant alpha1 glycine and alpha1beta2gamma2L GABAA receptors. METHODS Recombinant alpha1 glycine or alpha1beta2gamma2L GABAA receptors were expressed in Xenopus laevis oocytes and agonist-evoked currents recorded under voltage-clamp. Steroid modulation of currents evoked by GABA, or glycine, was quantified by determining the potency (EC50) and maximal effect of the compounds. RESULTS The anaesthetics minaxolone (EC50=1.3 microM), Org20599 (EC50=1.1 microM) and alphaxalone (EC50=2.2 microM) enhanced currents mediated by GABAA receptors. The anaesthetics also enhanced currents mediated by glycine receptors, although with higher EC50 values (minaxolone 13.1 microM; Org20599=22.9 microM and alphaxalone=27.8 microM). The maximal enhancement (to 780-950% of control) produced by the three steroids acting at the GABAA receptor was similar, but currents evoked by glycine were potentiated with increasing effectiveness by alphaxalone (199%) <Org20599 (525%) <minaxolone (1197%). The anaesthetic isomers, 5alpha-pregnan-3alpha-ol-20-one and 5beta-pregnan-3alpha-ol-20-one (eltanolone) enhanced GABAA receptor-mediated currents with similar potency and efficacy, but only the former enhanced glycine, the latter causing inhibition. The non-anaesthetic steroids 5alpha-pregnan-3beta-ol-20-one and 5beta-pregnan-3beta-ol-20-one modulated neither GABAA, nor glycine, receptors. CONCLUSIONS The data demonstrate that structure-activity relationships for steroid modulation at glycine and GABAA receptors differ. Comparing the EC50 values reported here with free plasma concentrations during steroid-induced anaesthesia indicates that a selective modulation of GABAA receptor activity is likely to occur in vivo.
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Affiliation(s)
- C J Weir
- Department of Anaesthesia, Division of Pathology and Neuroscience, Ninewells Hospital and Medical School, The University of Dundee, Dundee DD1 9SY, UK.
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15
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van Rijn CM, Willems-van Bree E. A four-ligand hypercube model to quantify allosteric interactions within the GABAA receptor complex. Eur J Pharmacol 2004; 485:43-51. [PMID: 14757122 DOI: 10.1016/j.ejphar.2003.11.044] [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: 11/24/2022]
Abstract
The aim of this study was to investigate the couplings between various binding sites on the GABA(A) receptor complex. We investigated combinations of three test compounds: (1) GABA (gamma-aminobutyric acid), (2) Org 20549 [(2 beta 3 alpha 5 alpha)-21hydroxy-3Hydroxy-2(4morpholinyl)pregnan-20one methane-sulphonate)], a neuroactive steroid and (3) retigabine (D-23129, N-(2-amino-4-(4-fluorobenzylamino)-phenyl) carbamic acid ethyl ester), a new antiepileptic drug. Receptor-binding assays were conducted using rat brain membranes. [3H]TBOB ([3H]-t-butyl-bicyclo-ortho-benzoate) was the tracer ligand. All three test compounds inhibited the binding of [3H]TBOB with EC(50)'s of 4.0, 98 and 23 microM, respectively. Isobolic analysis of the combination data showed that the three compounds act in synergy in displacing [3H]TBOB. These interactions could be described and quantified by a hypercube model in which each of the three test compounds and [3H]TBOB bind to different, allosterically coupled sites such that each of the test compounds allosterically displaces the tracer [3H]TBOB and allosterically enhances the affinity of any other test compound by a factor 4.4. The simultaneous binding of any two ligands enhances the affinity of the third by a factor 9. These results may contribute to the understanding of individual variability in drug responses and to the discussion about rational polytherapy.
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Affiliation(s)
- Clementina M van Rijn
- NICI/Department of Biological Psychology, University of Nijmegen, Post-box 9104, 6500 HE Nijmegen, The Netherlands.
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16
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Pau D, Belelli D, Callachan H, Peden DR, Dunlop JI, Peters JA, Guitart X, Gutierrez B, Lambert JJ. GABAA receptor modulation by the novel intravenous general anaesthetic E-6375. Neuropharmacology 2003; 45:1029-40. [PMID: 14614946 DOI: 10.1016/s0028-3908(03)00299-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
E-6375 (4-butoxy-2-[4-(2-cyanobenzoyl)-1-piperazinyl] pyrimidine hydrochloride) is a new intravenous general anaesthetic with an anaesthetic potency, in mice, comparable to propofol, or etomidate. Here, we examined the effect of E-6375 upon the GABAA receptor, a putative target of intravenous anaesthetic action. E-6375 reversibly enhanced GABA-evoked currents mediated by recombinant GABAA (alpha1beta2gamma2L) receptors expressed in Xenopus laevis oocytes, with little effect on NMDA- and kainate-evoked currents mediated by NR1a/NR2A and GluR1o/GluR2o glutamate receptors, respectively. E-6375 prolonged the decay of GABA-evoked miniature inhibitory postsynaptic currents recorded from rat Purkinje neurones demonstrating the anaesthetic also enhanced the activity of synaptic GABAA receptors. The GABA enhancing action of E-6375 on recombinant GABAA receptors was unaffected by the subtype of the alpha isoform (i.e. alphaxbeta2gamma2L; x=1-3) within the receptor, but was increased by the omission of the gamma2L subunit. Receptors incorporating beta2, or beta3, subunits were more sensitive to modulation by E-6375 than those containing the beta1 subunit. The selectivity of E-6375 was largely governed by the identity (serine or asparagine) of a single amino acid residue within the second transmembrane domain of the beta-subunit. The various in vivo actions of general anaesthetics may be mediated by GABAA receptor isoforms that have a differential distribution within the CNS. The identification of agents, such as E-6375, that discriminate between GABAA receptor subtypes may augur the development of general anaesthetics with an improved therapeutic profile.
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Affiliation(s)
- D Pau
- Neuroscience Institute, Department of Pharmacology and Neuroscience, Ninewells Hospital and Medical School, The University of Dundee, Dundee DD1 9SY, UK
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17
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Visser SAG, Gladdines WWFT, van der Graaf PH, Peletier LA, Danhof M. Neuroactive steroids differ in potency but not in intrinsic efficacy at the GABA(A) receptor in vivo. J Pharmacol Exp Ther 2002; 303:616-26. [PMID: 12388643 DOI: 10.1124/jpet.102.039610] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The objective of the present investigation was to characterize the in vivo EEG effects of (synthetic) neuroactive steroids on the basis of a recently proposed mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) model. After intravenous administration, the time course of the EEG effect of pregnanolone, 2beta-3alpha-5alpha-3-hydroxy-2-(2,2-dimethylmorpholin-4-yl)-pregnan-11,20-dione (ORG 21465), 2beta-3alpha-5alpha-21-chloro-3-hydroxy-2-(4-morpholinyl)-pregnan-20-one (ORG 20599), and alphaxalone was determined in conjunction with plasma concentrations in rats. For each neuroactive steroid the PK/PD correlation was described on the basis of a two-compartment pharmacokinetic model with an effect compartment to account for hysteresis. The observed concentration EEG effect relationships were biphasic and characterized with a mechanism-based pharmacodynamic model, which is based on a separation between the receptor activation process and the stimulus-response relationship. A single unique biphasic stimulus-response relationship could be identified for all neuroactive steroids, which was successfully described by a parabolic function. The receptor activation process was described by a hyperbolic function. Estimates for the maximum activation (e(PD)) were similar for the different neuroactive steroids but values of the potency estimate (K(PD)) ranged from 157 +/- 16 ng. ml(-1) for pregnanolone, 221 +/- 83 ng. ml(-1) for ORG 20599, and 483 +/- 42 ng. ml(-1) for alphaxalone to 1619 +/- 208 ng. ml(-1) for ORG 21465. A statistically significant correlation was observed between the in vivo potency and the IC(50) in an in vitro [(35)S]t-butylbicyclophosphorothionate binding assay (r = 0.91). It is concluded that the new PK/PD model constitutes a new mechanism-based approach to the quantification of the effects of (synthetic) neuroactive steroids in vivo effects. The results show that the neuroactive steroids differ in potency but not in intrinsic efficacy at the GABA(A) receptor in vivo.
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Affiliation(s)
- S A G Visser
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands
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18
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Visser SAG, Smulders CJGM, Reijers BPR, Van der Graaf PH, Peletier LA, Danhof M. Mechanism-based pharmacokinetic-pharmacodynamic modeling of concentration-dependent hysteresis and biphasic electroencephalogram effects of alphaxalone in rats. J Pharmacol Exp Ther 2002; 302:1158-67. [PMID: 12183676 DOI: 10.1124/jpet.302.3.1158] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The neuroactive steroid alphaxalone reveals a complex biphasic concentration-effect relationship using the 11.5 to 30 Hz frequency band of the electroencephalogram (EEG) as biomarker. The purpose of the present investigation was to develop a mechanism-based pharmacokinetic-pharmacodynamic model to describe this observation. The proposed model is based on receptor theory and aims to separate the drug-receptor interaction from the transduction of the initial stimulus into the observed biphasic response. Individual concentration-time courses of alphaxalone were obtained in combination with continuous recording of the EEG parameter. Alphaxalone was administered intravenously in various dosages. The pharmacokinetics were described by a two-compartment model, and parameter estimates for clearance, intercompartmental clearance, volume of distribution 1 and 2 were 158 +/- 29 ml. min(-1). kg(-1), 143 +/- 31 ml. min(-1). kg(-1), 122 +/- 20 ml. kg(-1) and 606 +/- 48 ml. kg(-1), respectively. Concentration-effect relationships exhibited a biphasic pattern and delay in onset of effect. The hysteresis was described on the basis of an effect-compartment model with C(max) as covariate. The pharmacodynamic model consisted of a receptor model, featuring a monophasic saturable receptor activation model in combination with a biphasic stimulus-response model. The in vivo affinity (K(PD)) was estimated at 432 +/- 26 ng. ml(-1). Unique parameter estimates were obtained that were independent of the dose and the duration of the infusion. In conclusion, we have shown that this mechanism-based approach, which separates drug- and system-related properties in vivo, was successfully applied for the characterization of the biphasic effect versus time patterns of alphaxalone. The model should be of use in the characterization of other biphasic responses.
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Affiliation(s)
- S A G Visser
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands
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19
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Lambert JJ, Harney SC, Belelli D, Peters JA. Neurosteroid modulation of recombinant and synaptic GABAA receptors. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2002; 46:177-205. [PMID: 11599300 DOI: 10.1016/s0074-7742(01)46063-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Certain pregnane steroids are now established as potent, positive allosteric modulators of the gamma-aminobutyric acid type A (GABAA) receptor. These compounds are known to be synthesized in the periphery by endocrine glands, such as the ovaries and the adrenal glands, and can rapidly cross the blood-brain barrier. Therefore, such steroids could act as endogeneous modulators of the major inhibitory receptor in the mammalian central nervous system. However, the demonstration that certain neurons and glia can synthesize the pregnane steroids (i.e., neurosteroids) additionally suggests that they may serve a paracrine role by influencing GABAA-receptor function through their local release in the brain itself. Here, we demonstrate that these neurosteroids are highly selective and extremely potent modulators of the GABAA receptor. The subunit composition of the GABAA receptor may influence the actions of the neurosteroids, particularly when considering concentrations of these agents thought to occur physiologically, which may underlie their reported differential effects at certain inhibitory synapses. However, recent work suggests that the phosphorylation status of either the synaptic GABAA receptor or its associated proteins may also influence neurosteroid sensitivity; these findings are discussed. Upon administration, the neurosteroids exhibit clear behavioral effects, including sedation, anticonvulsant actions, and behaviors predictive of anxiolysis; when given at high doses, they induce general anesthesia. Numerous synthetic steroids have been synthesized in an attempt to therapeutically exploit these properties, and these data are reviewed in this chapter. However, targeting the brain enzymes that synthesize and metabolize the neurosteroids may offer a new approach to exploit this novel endocrine-paracrine neurotransmitter interaction.
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Affiliation(s)
- J J Lambert
- Department of Pharmacology and Neuroscience, Ninewells Hospital and Medical School, Dundee University, Dundee, DD1 9SY Scotland
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20
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Lambert JJ, Belelli D, Harney SC, Peters JA, Frenguelli BG. Modulation of native and recombinant GABA(A) receptors by endogenous and synthetic neuroactive steroids. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 37:68-80. [PMID: 11744075 DOI: 10.1016/s0165-0173(01)00124-2] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Upon administration, certain pregnane steroids produce clear behavioural effects including, anxiolysis, sedation, analgesia, anaesthesia and are anti-convulsant. This behavioural profile is characteristic of compounds that act to enhance the actions of GABA acting at the GABA(A) receptor. In agreement, numerous studies have now demonstrated these steroids to be potent, positive allosteric modulators of the GABA(A) receptor. The pregnane steroids are synthesized in the periphery by endocrine glands such as the adrenals and the ovaries, but are also made by neurons and glial cells in the central nervous system itself. Hence, these compounds could play both an endocrine and a paracrine role to influence neuronal excitability by promoting inhibition. Here we review evidence that the pregnane steroids are highly selective and extremely potent GABA(A) receptor modulators and that their effects at 'physiological' concentrations (low nanomolar) may be influenced by the subunit composition of the GABA(A) receptor. This feature may underlie recent findings demonstrating the effects of the neurosteroids on inhibitory synaptic transmission to be brain region dependent, although recent reports suggest that phosphorylation mechanisms may additionally influence neurosteroid sensitivity of the GABA(A) receptor. Numerous synthetic steroids have been synthesized in an attempt to therapeutically exploit the behavioural effects of the pregnane steroids and progress with this approach will be discussed. However, the demonstration that the steroids may be made within the central nervous system offers the alternative strategy of targeting the enzymes that synthesize/metabolise the neurosteroids to exploit this novel endocrine/paracrine interaction.
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Affiliation(s)
- J J Lambert
- Department of Pharmacology and Neuroscience, Neurosciences Institute, University of Dundee, Ninewells Hospital and Medical School, Ninewells Hospital, DD1 9SY, Dundee, UK.
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21
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Goodchild CS, Robinson A, Nadeson R. Antinociceptive properties of neurosteroids IV: pilot study demonstrating the analgesic effects of alphadolone administered orally to humans. Br J Anaesth 2001; 86:528-34. [PMID: 11573627 DOI: 10.1093/bja/86.4.528] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Fourteen patients scheduled for orthopaedic knee reconstruction surgery were enrolled in a prospective, double-blind, randomized study in which they received alphadolone (25-500 mg, n = 9) or placebo (lactose, n = 5) given orally 1 h after operation. All the subjects received a standardized general anaesthetic and the same type of surgery followed by physiotherapy using a continuous passive movement machine. Morphine was administered intravenously after operation by patient-controlled analgesia. Verbal rating and visual analogue scores assessed pain experiences for 6 h. Orally administered alphadolone up to 500 mg caused no increase in sedation, respiratory depression, nausea or vomiting. The experiences of these side-effects were all rated as none, mild or moderate. Orally administered alphadolone caused statistically significant reductions in morphine use and simultaneous highly significant reductions in pain scores. We conclude that alphadolone is a useful analgesic in humans when given by the oral route.
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Affiliation(s)
- C S Goodchild
- Department of Anaesthesia, Monash University, Monash Medical Centre, Clayton, Victoria, Australia
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22
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Anderson A, Boyd AC, Clark JK, Fielding L, Gemmell DK, Hamilton NM, Maidment MS, May V, McGuire R, McPhail P, Sansbury FH, Sundaram H, Taylor R. Conformationally constrained anesthetic steroids that modulate GABA(A) receptors. J Med Chem 2000; 43:4118-25. [PMID: 11063608 DOI: 10.1021/jm000977e] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Various cyclic ether and other 3 alpha-hydroxyandrostane derivatives bearing a conformationally constrained hydrogen-bonding moiety were prepared. Their anesthetic potency and their binding affinity for GABA(A) receptors, measured by intravenous administration to mice and inhibition of [(35)S]TBPS binding to rat whole brain membranes, were compared with that of known anesthetic 3 alpha-hydroxypregnan-20-ones. Synthetic steroids with similar in vitro and in vivo activities to the endogenous 3 alpha-hydroxypregnan-20-ones all had an ether oxygen on the beta-face of the steroid D-ring. These results suggest that for optimal GABA(A) receptor modulation, the hydrogen bond-accepting substituent should be near perpendicular to the plane of the D-ring on the beta-face of the steroid.
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Affiliation(s)
- A Anderson
- Research and Development, Organon Laboratories Ltd., Newhouse, Motherwell, Lanarkshire ML1 5SH, Scotland, UK
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23
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Abstract
The molecular mechanisms of general anaesthetics have remained largely obscure since their introduction into clinical practice just over 150 years ago. This review describes the actions of general anaesthetics on mammalian neurotransmitter-gated ion channels. As a result of research during the last several decades, ligand-gated ion channels have emerged as promising molecular targets for the central nervous system effects of general anaesthetics. The last 10 years have witnessed an explosion of studies of anaesthetic modulation of recombinant ligand-gated ion channels, including recent studies which utilize chimeric and mutated receptors to identify regions of ligand-gated ion channels important for the actions of general anaesthetics. Exciting future directions include structural biology and gene-targeting approaches to further the understanding of general anaesthetic molecular mechanisms.
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Affiliation(s)
- M. D. Krasowski
- />Committee on Neurobiology, University of Chicago, Whitman Laboratory, 915 East 57th Street, Chicago (Illinois 60637, USA), e-mail: , , , , US
| | - N. L. Harrison
- />Committee on Neurobiology, University of Chicago, Whitman Laboratory, 915 East 57th Street, Chicago (Illinois 60637, USA), e-mail: , , , , US
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Van Rijn CM, Willems-van Bree E, Zwart JP, Rodrigues de Miranda JF, Dirksen R. A molecular model for the synergic interaction between gamma-aminobutyric acid and general anaesthetics. Eur J Pharmacol 1999; 371:213-26. [PMID: 10357259 DOI: 10.1016/s0014-2999(99)00178-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Within the context of the discussion about rational polytherapy, we determined the effects of four anaesthetics on the binding of [3H]t-butylbicycloorthobenzoate ([3H]TBOB) to the GABA(A) receptor complex in the presence of several concentrations of GABA (gamma-aminobutyric acid), in order to build a molecular model that can describe and quantify the interactions between the compounds. The empirical isobole method revealed that GABA and the anaesthetics acted synergically in displacing [3H]TBOB. This synergy could be described by a simple molecular model in which both GABA and the anaesthetics displaced [3H]TBOB allosterically and in which GABA allosterically enhanced the binding of the anaesthetics. To get information about the interaction between GABA and anaesthetics, we used [3H]TBOB as a tracer ligand. The model indicated that GABA enhanced the affinity of thiopental 3.0-fold, propofol 5.0-fold, the neuroactive steroids Org 20599 3.5-fold and Org 20549 13-fold. Insight into the molecular mechanism and strength of these interactions can help clinicians to choose therapeutically optimal drug and dose combinations: a step towards rational polytherapy.
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Affiliation(s)
- C M Van Rijn
- NICI/Department Psychology, University of Nijmegen, HE Nijmegen, The Netherlands.
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25
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Gasior M, Carter RB, Witkin JM. Neuroactive steroids: potential therapeutic use in neurological and psychiatric disorders. Trends Pharmacol Sci 1999; 20:107-12. [PMID: 10203866 DOI: 10.1016/s0165-6147(99)01318-8] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neuroactive steroids are a novel class of positive allosteric modulators of the GABAA receptor. Although neuroactive steroids are endogenous neuronal modulators, synthetic entities with improved oral bioavailability have recently been developed. These compounds demonstrate efficacy as anticonvulsants against a range of convulsant stimuli and demonstrate anti-epileptogenic activity in a kindling model of epilepsy. Efficacy has also been reported in preclinical models of anxiety, insomnia, migraine and drug dependence. Clinical evidence to date is generally supportive of these findings and indicates that neuroactive steroids are generally well tolerated. Taken as a whole, current data suggest that neuroactive steroids could have a future role in clinical practice. In this article, Maciej Gasior, Richard Carter and Jeffrey Witkin review preclinical and clinical evidence that forms the basis for predicting the potential therapeutic application of neuroactive steroids.
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Affiliation(s)
- M Gasior
- Behavioral Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
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26
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Anderson A, Boyd AC, Byford A, Campbell AC, Gemmell DK, Hamilton NM, Hill DR, Hill-Venning C, Lambert JJ, Maidment MS, May V, Marshall RJ, Peters JA, Rees DC, Stevenson D, Sundaram H. Anesthetic activity of novel water-soluble 2 beta-morpholinyl steroids and their modulatory effects at GABAA receptors. J Med Chem 1997; 40:1668-81. [PMID: 9171876 DOI: 10.1021/jm960733n] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
(3 alpha,5 alpha)-3-Hydroxypregnan-20-ones and (3 alpha,5 alpha)-3-hydroxypregnane-11,20-diones bearing a 2 beta-morpholinyl substituent were synthesized, and the utility of these steroids as anesthetic agents was evaluated through determination of their potency and duration of hypnotic activity in mice after intravenous administration. Alkylation of the morpholinyl substituent or chlorination at C-21 afforded the novel amino steroids (2 beta,3 alpha,5 alpha)-3-hydroxy-2-(2,2-dimethyl-4-morpholinyl)-pregnane-11,20-dione (19) and (2 beta,3 alpha,5 alpha)-21-chloro-3-hydroxy-2-(4-morpholinyl)pregnan-20-one (37) that were more potent and advantageously produced shorter sleep times than related compounds which were previously reported. Furthermore, salts of these and other amino steroids generally retained good aqueous solubility. In a radioligand binding assay the compounds inhibited the specific binding of [35S]-tert-butyl bicyclophosphorothionate to rat whole brain membranes, and in an electrophysiological assay they potentiated GABAA receptor-mediated currents recorded from voltage-clamped bovine chromaffin cells. These in vitro results are consistent with the anesthetic activity of the amino steroids being related to their modulatory effects at GABAA receptors.
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Affiliation(s)
- A Anderson
- Scientific Development Group, Oganon Laboratories Ltd., Newhouse, Lanarkshire, Scotland, UK
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