1
|
Childs MD, Luyt LG. A Decade's Progress in the Development of Molecular Imaging Agents Targeting the Growth Hormone Secretagogue Receptor. Mol Imaging 2020; 19:1536012120952623. [PMID: 33104445 PMCID: PMC8865914 DOI: 10.1177/1536012120952623] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The growth hormone secretagogue receptor 1a (GHSR), also called the ghrelin receptor, is a G protein-coupled receptor known to play an important metabolic role in the regulation of various physiological processes, including energy expenditure, growth hormone secretion, and cell proliferation. This receptor has been implicated in numerous health issues including obesity, gastrointestinal disorders, type II diabetes, and regulation of body weight in patients with Prader-Willi syndrome, and there has been growing interest in studying its mechanism of behavior to unlock further applications of GHSR-targeted therapeutics. In addition, the GHSR is expressed in various types of cancer including prostate, breast, and testicular cancers, while aberrant expression has been reported in cardiac disease. Targeted molecular imaging of the GHSR could provide insights into its role in biological processes related to these disease states. Over the past decade, imaging probes targeting this receptor have been discovered for the imaging modalities PET, SPECT, and optical imaging. High-affinity analogues of ghrelin, the endogenous ligand for the GHSR, as well as small molecule inhibitors have been developed and evaluated both in vitro and in pre-clinical models. This review provides a comprehensive overview of the molecular imaging agents targeting the GHSR reported to the end of 2019.
Collapse
Affiliation(s)
- Marina D Childs
- Department of Chemistry, University of Western Ontario, London, Ontario, Canada
| | - Leonard G Luyt
- Department of Chemistry, University of Western Ontario, London, Ontario, Canada.,Lawson Health Research Institute, London, Ontario, Canada.,Department of Oncology, University of Western Ontario, London, Ontario, Canada.,Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
2
|
Vashishat R, Chabba S, Aswal VK, Mahajan RK. Probing molecular interactions of tetracaine with surface active ionic liquid and subsequent formation of vesicle in aqueous medium. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.08.062] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
3
|
Yamanaka M, Takajo Y, Ono S, Matsuki H, Kaneshina S. Volume study on the exclusion of lithium naphthylsulfonate from lithium decylsulfonate micelles. Colloid Polym Sci 2006. [DOI: 10.1007/s00396-006-1615-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
4
|
Frangopol PT, Mihăilescu D. Interactions of some local anesthetics and alcohols with membranes. Colloids Surf B Biointerfaces 2001; 22:3-22. [PMID: 11438236 DOI: 10.1016/s0927-7765(01)00153-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A review of the results obtained by our group in the last decade regarding the interactions of procaine, lidocaine, dibucaine and tetracaine with membranes is presented in the context of the literature data. The action upon membranes, in first approximation monomolecular film of stearic acid spread at the air/water interface used as a membrane model, the modification of biomembrane structure and function using diffraction methods, lipid phase transition, fluidity of lipids and proteins, membrane expansion and platelet aggregation were studied. The thermodynamic knowledge of membrane-alcohol interactions improved by using highly sensitive calorimetric techniques are briefly reported. One of the main conclusions is that the physical state of a monolayer model membrane was the result of competitive interactions between film-film and film-substrate interactions. It was taken into account that local anesthetics, such as lidocaine, carbisocaine, mesocaine, showed changes in the bilayer structure, reflected in macroscopic mechanical properties. This restructuring of the lipid bilayer has a significant influence on the operation of functional subunits, e.g. ionic channels formed by gramicidin. The results support the concept of non-specific interactions of local anesthetics with lipid bilayers. The theoretical modeling of the interactions of local anesthetics is closely compared with experimental data. Our new theory of relaxation for these interactions is using a non-archimedean formalism based on a process resulting from superpositions of different component processes which take place at different scales of time.
Collapse
Affiliation(s)
- P T. Frangopol
- Department of Chemical Physics, Faculty of Chemistry, 'Babes-Bolyai' University, 11, Aranyi Janos Str., R-3400, Cluj-Napoca, Romania
| | | |
Collapse
|
5
|
Abstract
The molecular-level organization of mixed and pure saturated symmetric chain 1,2-diacyl-sn-glycero-3-phosphocholines (PCs) adsorbed at a carbon tetrachloride-aqueous interface is explored by probing the hydrocarbon chain conformation within the adsorbed layer. PCs of the chain lengths found most frequently in biological systems, which in pure form are seen to form either very well-ordered or disordered layers, are observed in these studies to assemble into interfacial layers ranging from disordered to ordered states when mixed in various proportions. Independently, while C(16) and shorter chain PCs tend to form disordered layers, a strong increase in ordering is observed for C(18) and longer chain PCs in which the hydrocarbon chains are found to be primarily in an all trans conformation. Pure C(17)-PCs adsorbed at the interface produce layers with an intermediate degree of chain ordering. The ability to tune interfacial layer properties in mixed systems as a function of molecular composition, including PC chain length as demonstrated here, is an important mechanism by which surface characteristics of oil-water emulsion systems can be controlled both in vivo and in numerous commercial applications.
Collapse
Affiliation(s)
- B L Smiley
- Department of Chemistry, University of Oregon, Eugene, Oregon 97403, USA
| | | |
Collapse
|
6
|
Matsuki H, Shimada K, Kaneshina S, Kamaya H, Ueda I. Difference in surface activities between uncharged and charged local anesthetics: correlation with their anesthetic potencies. Colloids Surf B Biointerfaces 1998. [DOI: 10.1016/s0927-7765(98)00046-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
7
|
Matsuki H, Kaneshina S, Kamaya H, Ueda I. Partitioning of Charged Local Anesthetics into Model Membranes Formed by Cationic Surfactant: Effect of Hydrophobicity of Local Anesthetic Molecules. J Phys Chem B 1998. [DOI: 10.1021/jp9804190] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hitoshi Matsuki
- Department of Anesthesia, Department of Veterans Administration Medical Center, and University of Utah School of Medicine, Salt Lake City, Utah 84148, and Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Minamijosanjima, Tokushima 770, Japan
| | - Shoji Kaneshina
- Department of Anesthesia, Department of Veterans Administration Medical Center, and University of Utah School of Medicine, Salt Lake City, Utah 84148, and Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Minamijosanjima, Tokushima 770, Japan
| | - Hiroshi Kamaya
- Department of Anesthesia, Department of Veterans Administration Medical Center, and University of Utah School of Medicine, Salt Lake City, Utah 84148, and Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Minamijosanjima, Tokushima 770, Japan
| | - Issaku Ueda
- Department of Anesthesia, Department of Veterans Administration Medical Center, and University of Utah School of Medicine, Salt Lake City, Utah 84148, and Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Minamijosanjima, Tokushima 770, Japan
| |
Collapse
|
8
|
Ohki S, Ohshima H. Competitive adsorption of Ca2+ and local anesthetics on lipid membrane surfaces. Colloids Surf B Biointerfaces 1996. [DOI: 10.1016/0927-7765(95)01231-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
9
|
Yamanaka M, Matsuki H, Kaneshina S. Volume Study on the Micelle Formation of Local Anesthetic Dibucaine Hydrochloride and Dodecyltrimethylammonium Chloride Mixtures. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1995. [DOI: 10.1246/bcsj.68.2159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
10
|
Effect of pressure on the colloidal solution behavior of aqueous local anesthetic tetracaine solutions. Colloids Surf A Physicochem Eng Asp 1995. [DOI: 10.1016/0927-7757(94)03076-c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
11
|
Ueda I, Chiou JS, Krishna PR, Kamaya H. Local anesthetics destabilize lipid membranes by breaking hydration shell: infrared and calorimetry studies. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1190:421-9. [PMID: 8142445 DOI: 10.1016/0005-2736(94)90103-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Differential scanning calorimetry (DSC) showed that local anesthetics decreased the pretransition (L beta'-->P beta') temperature of dipalmitoylphosphatidylcholine (DPPC) vesicle membranes four- to five-fold more than the main transition (P beta'-->L alpha) temperature. Because pretransition is mainly a change in the hydrophilic head property (tilted-rippled), the stronger effect on the pretransition suggests that the primary action site of local anesthetics is the lipid-water interface. The interfacial effect was analyzed by Fourier-transform infrared spectroscopy (FTIR) in water-in-oil (CCl4) reversed micelles. FTIR showed that the local anesthetics released hydrogen-bonded water molecules from the phosphate (P = O bands) and glycerol (sn-2 C = O) moieties. The N-H stretching band of the local anesthetics was deconvoluted into two bands: hydrogen bonded to the phosphate moiety of the lipid and free (unbound to lipid). The formation constants between lipid P = O and anesthetic N-H were estimated in CCl4 from the spectral changes: 110 M-1 for lidocaine and 250 M-1 for dibucaine. This small difference in the formation constants cannot explain the ten-fold stronger effect on the phase-transition temperature of dibucaine over lidocaine. By comparing the local anesthetic adsorption to the air/water interface in the presence and absence of lipid monolayers, we have previously shown (Lin et al. (1980) Biochim. Biophys. Acta 598, 51-65) that lipid-anesthetics interaction involves three forces: lipophilic effect, hydrophobic effect, and anesthetic-anesthetic interaction. The anesthetic potency depends mainly on the hydrophobic effect (the difference in the standard molar free energies of local anesthetics in water and at the interface) and anesthetic-anesthetic interaction energy. The anesthetic-anesthetic interaction means cooperativity of local anesthetics for the interfacial density: local anesthetics condense at the membrane surface when there are enough anesthetic molecules present at the interface to attract more anesthetics. The present data suggest that anesthetic action is directed to the interface between water and macromolecule, whether it is lipid membranes or proteins.
Collapse
Affiliation(s)
- I Ueda
- Anesthesia Service 112A, VA Medical Center, Salt Lake City, UT
| | | | | | | |
Collapse
|
12
|
Kaminoh Y, Inoue T, Ma SM, Ueda I, Lin SH. Membrane-buffer partition coefficients of tetracaine for liquid-crystal and solid-gel membranes estimated by direct ultraviolet spectrophotometry. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 946:337-44. [PMID: 3207749 DOI: 10.1016/0005-2736(88)90409-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The membrane-buffer partition coefficient of tetracaine was measured by direct ultraviolet spectrophotometry in dimyristoylphosphatidylcholine unilamellar liposomes at temperatures above and below the main phase transition. The partition coefficients of uncharged tetracaine to solid-gel (18 degrees C) and liquid-crystal (30 degrees C) membranes were 6.9 x 10(4) and 1.2 x 10(5), respectively. Despite the general assumption that local anesthetic binding to the solid membrane is negligible, this study showed that the solid membrane binding amounts to 57.5% of the liquid membrane binding. Binding of the charged form to the liquid or solid membrane was not detectable under the present experimental condition of 0.03 mM tetracaine bulk concentration. The present method measures metachromasia of local anesthetics when bound to lipid membranes. Its advantage is that the separation of the vesicles from the solution is not required. A linearized equation is presented that estimates the partition coefficient or binding constant graphically from a linear plot of the absorbance data. The method is applicable for estimation of drug partition when a measurable spectral change occurs due to complex formation.
Collapse
Affiliation(s)
- Y Kaminoh
- Department of Anesthesia, University of Utah School of Medicine, Salt Lake City
| | | | | | | | | |
Collapse
|
13
|
Ichikawa O. Enhancement of local anaesthesia action by organic acid salts. (II): Aspect of kinetics in the claw nerve membrane of crayfish. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1987; 95:121-31. [PMID: 2444179 DOI: 10.3109/13813458709104524] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The anaesthetic action of procaine on the crayfish claw nerve was studied electrophysiologically. The onset time of conduction block (block time) was shortened and the minimum dose of procaine required for the blockade was significantly reduced in the presence of monocarboxylate anions. To investigate the mechanism of this anaesthetic enhancement, the action of procaine was considered on the basis of a simple Langmuir-type adsorption model. Rate constants in the model were estimated by observing the time course of procaine desorption from the nerve using the UV light absorption technique. The dependence of block time on procaine concentration which was simulated from the model corresponded quite well to the electrophysiological data. The model suggested the following two points. 1. The anaesthetic enhancement by some organic anions could be explained by the acceleration of procaine adsorption and lowering of the critical adsorption ratio. 2. The maximum adsorption of procaine observed was about 40 mumol per 1 g wet weight of the nerve, the value of which corresponded to 1:1 adsorption of procaine to phospholipids in the membrane.
Collapse
Affiliation(s)
- O Ichikawa
- Department of Physiology, Tottori University, School of Medicine, Yonago, Japan
| |
Collapse
|
14
|
Manabe A, Nakayama S, Sakamoto K. Effects of essential oils on erythrocytes and hepatocytes from rats and dipalmitoyl phosphatidylcholine-liposomes. JAPANESE JOURNAL OF PHARMACOLOGY 1987; 44:77-84. [PMID: 3626186 DOI: 10.1254/jjp.44.77] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The effect of essential oils, eugenol, thymol and menthol, on erythrocytes, hepatocytes, dipalmitoyl phosphatidylcholine (DPPC)-liposomes and surface tension were studied at various concentrations. Maximal inhibition of eugenol, thymol and menthol on the hypotonic hemolysis in rat erythrocytes were observed at a concentration of 2 mM, 1 mM and 1 mM, respectively. Eugenol at 4 mM and thymol at 2 mM caused an acceleration of hypotonic hemolysis. In isolated rat hepatocytes, thymol caused an increase in GOT leakage, but eugenol at 4 mM and menthol at 0.1 and 0.4 mM inhibited the GOT leakage. The leakage of GPT from hepatocytes was inhibited by eugenol at 0.1 mM and 0.4 to 4 mM and menthol at 0.1 to 0.6 mM. The inhibition of eugenol and menthol on the LDH leakage in hepatocytes were observed at a concentration of 0.001 to 4 mM and 0.1, 0.4 and 0.6 mM, respectively. Thymol caused no change in GPT and LDH leakage. Eugenol, thymol and menthol indicated a depression of surface tension at a concentration of 0.1 mM. The rank by order of surface activity was eugenol greater than thymol. Eugenol, thymol and menthol depressed the phase-transition temperature of DPPC-liposomes. The depression of phase-transition temperature by thymol was greater than that by eugenol and menthol. These results suggest the periapical tissue damage produced by essential oils may be related to membrane lysis and surface activity and that their tissue penetration may be related to membrane affinity and lipid solubility.
Collapse
|
15
|
|
16
|
Guilmin T, Goormaghtigh E, Brasseur R, Caspers J, Ruysschaert JM. Evaluation of the anesthetic-lipid association constant. A monolayer approach. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 685:169-76. [PMID: 6460528 DOI: 10.1016/0005-2736(82)90094-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A new approach is presented which allows to describe the binding of different local anesthetics to lipids. Lipids (DL- alpha-dipalmitoylphosphatidylcholine, phosphatidylserine, cardiolipin) are spread at the air-water interface and the anesthetic (procaine, butacaine, tetracaine) injected into the aqueous subphase. The equilibrium constants associated to the interfacial reaction: D+ (subphase) +L- (monolayer) in equilibrium DL (monolayer) (where D+ denotes the anesthetics, L- the lipid anionic site and DL the complex) are calculated from an experimental evaluation of the surface potential of the lipid monolayer. This mode of determination is based essentially on the good correlation between the experimental values of the surface potential and the theoretical predictions from the Gouy-Chapman theory. Fluorescence measurements on liposomes are carried out in order to locate the position of the drug in the lipid layer. This method can be extended to any positively charged drug-anionic lipid interaction.
Collapse
|