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Michael Gochfeld - One of the best experts on this subject based on the ideXlab platform.
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Stakeholder Participation in Research Design and Decisions: Scientists, Fishers, and Mercury in Saltwater Fish
EcoHealth, 2013Co-Authors: Joanna Burger, Michael Gochfeld, Tom FoteAbstract:Individuals who Fish and eat self-caught Fish make decisions about where to Fish, the type to eat, and the quantity to eat. Federal and state agencies often issue consumption advisories for some Fish with high mercury (Hg) concentrations, but seldom provide either the actual metal levels to the general public, or identify the Fish that have low contaminant levels. Community participatory research is of growing importance in defining, studying, and resolving complex exposure and risk issues, and this paper is at the intersection of traditional stakeholder approaches and community-based participatory research. The objective of this paper is to describe the process whereby stakeholders (Fishers), were involved in directing and refining research questions to address their particular informational needs about mercury levels in Fish, potential risks, and methods to maintain health, by balancing the risks and benefits of Fish consumption. A range of stakeholders, mainly individual Fishers, Fishing organizations, and other scientists, were involved at nearly every stage. Community participants influenced many aspects of the design and implementation of the research, in the determination of which Fish species to sample, in the collection of the samples, and in the final analyses and synthesis, as well as the communication of results and implications of the research through their Fishing club publications, talks and gatherings. By involving the most interested and affected communities, the data and conclusions are relevant to their needs because the Fish examined were those they ate and wanted information about, and directly address concerns about the risk from consuming self-caught Fish. Although mercury levels in Fish presumed to be high in mercury are known, little information was available to the Fishermen on mercury levels in Fish that were low and thus provided little risk to their families. While community participatory research is more time-consuming and expensive than traditional scientific research, both the process and results are better scientifically in terms of community relevance.
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Selenium/mercury molar ratios in freshwater, marine, and commercial Fish from the USA: variation, risk, and health management
Reviews on environmental health, 2013Co-Authors: Joanna Burger, Michael GochfeldAbstract:Fish provide healthy protein as well as recreational and cultural benefits, but can also contain mercury (Hg), polychlorinated biphenyls (PCBs), and other contaminants that have adverse effects on humans and other organisms, particularly developing fetuses. Recently, some authors have suggested that a molar excess of selenium (Se) [e.g., selenium/mercury (Se/Hg) molar ratio >1] confers protection from Hg toxicity derived from Fish consumption. Herein, we review our studies of Hg and Se in freshwater, marine, and commercial Fish (mainly marine), examining the following: (1) whether and how Se/Hg molar ratios vary among species; (2) whether and how the molar ratios vary within species; (3) whether the molar ratios differ between freshwater and Saltwater Fish; (4) whether mean molar ratio values provide a reliable indication of potential risk to Fish consumers; and (5) whether mean Se/Hg molar ratios are sufficiently constant (e.g., low variation) to allow for use in risk assessment, risk management, or risk communication. In Saltwater Fish, mean Se/Hg molar ratios varied from 0.3 in mako shark to 68.1 in whiting. For freshwater Fish, the mean ratios varied from 0.68 in bowfin to 20.8 in black crappie. Commercial seafood (mainly Saltwater) showed great variation in ratios; shrimp and scallops had very high ratios. There was somewhat less variability in the ratios for freshwater Fish compared with the Fish from Saltwater, but there was no overall predictable difference in variation in Se/Hg molar ratios. For both Saltwater and freshwater Fish, some species with mean molar ratios above 1 had a significant proportion of individual Fish with molar ratios below 1. Overall, this indicates great variation in measures of central tendencies and in measures of dispersion. We suggest that relying on the Se/Hg molar ratio as a method of predicting reduced risk from Hg toxicity is problematic because of the great variation among and within Fish species, and the variation is not predictable because Hg varies by season, size of the Fish, and location of the Fish (which is not available for commercial Fish). With the high variation in ratios, and low predictability, the ratios are currently not useful for risk assessment and risk management, and vulnerable individuals cannot rely on mean Se/Hg molar ratios for protection from Hg toxicity.
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interspecific and intraspecific variation in selenium mercury molar ratios in Saltwater Fish from the aleutians potential protection on mercury toxicity by selenium
Science of The Total Environment, 2012Co-Authors: Joanna Burger, Michael Gochfeld, Christian Jeitner, Mark Donio, Taryn PittfieldAbstract:Abstract A number of factors affect the consumption risk from mercury in Fish, including mercury levels, seasonal patterns of mercury concentrations, human consumption patterns, and sensitive populations (e.g. pregnant women, fetuses, young children, and yet unknown genetic factors). Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for Saltwater Fish. We examine levels of mercury and selenium in several species of Fish and seabirds from the Aleutians (Alaska), determine selenium:mercury molar ratios, and examine species-specific and individual variation in the ratios as a means of exploring the use of the ratio in risk assessment and risk management. Variation among species was similar for mercury and selenium. There was significant interspecific and intraspecific variation in selenium:mercury molar ratios for Fish, and for birds. The mean selenium:mercury molar ratios for all Fish and bird species were above 1, meaning there was an excess of selenium relative to mercury. It has been suggested that an excess of selenium confers some protective advantage for salt water Fish, although the degree of excess necessary is unclear. The selenium:mercury molar ratio was significantly correlated negatively with total length for most Fish species, but not for dolly varden. Some individuals of Pacific cod, yellow irish lord, rock greenling, Pacific halibut, dolly varden, and to a lesser extent, flathead sole, had selenium:mercury ratios below 1. No bird muscle had an excess of mercury (ratio below 1), and only glaucous-winged gull and pigeon guillemot had ratios between 1 and 5. There was a great deal of variation in selenium:mercury molar ratios within Fish species, and within bird species, making it difficult and impractical to use these ratios in risk assessment or management, for Fish advisories, or for consumers, particularly given the difficulty of interpreting the ratios.
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selenium and mercury molar ratios in Saltwater Fish from new jersey individual and species variability complicate use in human health Fish consumption advisories
Environmental Research, 2012Co-Authors: Joanna Burger, Michael GochfeldAbstract:Balancing risk versus benefits to humans and other organisms from consuming Fish is a national concern in the USA, as well as in many other parts of the world. Protecting public health is both a federal and state responsibility, and states respond by issuing Fish consumption advisories, particularly for mercury. Recently it has been emphasized that the protective role of selenium against mercury toxicity depends on their molar ratios, which should be evaluated as an indication of selenium's protective capacity, and incorporated in risk assessments for Fish consumption. However, there is no single “protective” ratio agreed upon. In this paper we examine the selenium:mercury (Se:Hg) molar ratios in a wide range of Saltwater Fish caught and eaten by recreational Fishers along the New Jersey coast. We were particularly interested in interspecific and intraspecific variability, and whether the molar ratios were consistent within a species, allowing for its use in managing risk. The selenium–mercury molar ratio showed significant variation among and within Fish species. The molar ratio decreased with the size of the Fish species, decreased with the mercury levels, and within a Fish species, the selenium:mercury ratio decreased with Fish size. As an essential element, selenium undergoes some homeostatic regulation, but it is also highly toxic. Within species, mercury level tends to increase with size, accounting for the negative relationship between size and ratio. This variability may make it difficult to use the selenium:mercury molar ratio in risk assessment, risk management, and risk communication at this time, and more information is needed on how mercury and selenium actually interact and on the relationship between the molar ratios and health outcomes.
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locational differences in mercury and selenium levels in 19 species of Saltwater Fish from new jersey
Journal of Toxicology and Environmental Health, 2011Co-Authors: Joanna Burger, Christian Jeitner, Michael GochfeldAbstract:Individuals who Fish, and their families that ingest self-caught Fish, make decisions about where to Fish, what type of Fish to eat, and the quantity of Fish to eat. While federal and state agencies often issue consumption advisories for some Fish with high mercury (Hg) concentrations, advisories seldom provide the actual metal levels to the general public. There are few data for most Saltwater Fish, and even less information on variations in Hg levels in Fish within a state or geographical region. The objective of this study was to provide Hg concentrations from 19 species of Fish caught in different locations in New Jersey to (1) test the hypothesis that mean metal levels vary geographically, (2) provide this information to individuals who Fish these coastal waters, and (3) provide a range of values for risk assessors who deal with Saltwater Fish exposure in the Northeastern United States. Selenium (Se) was also examined because of its purported moderating effect on the toxicity of Hg. Hg levels showed ...
Joanna Burger - One of the best experts on this subject based on the ideXlab platform.
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Stakeholder Participation in Research Design and Decisions: Scientists, Fishers, and Mercury in Saltwater Fish
EcoHealth, 2013Co-Authors: Joanna Burger, Michael Gochfeld, Tom FoteAbstract:Individuals who Fish and eat self-caught Fish make decisions about where to Fish, the type to eat, and the quantity to eat. Federal and state agencies often issue consumption advisories for some Fish with high mercury (Hg) concentrations, but seldom provide either the actual metal levels to the general public, or identify the Fish that have low contaminant levels. Community participatory research is of growing importance in defining, studying, and resolving complex exposure and risk issues, and this paper is at the intersection of traditional stakeholder approaches and community-based participatory research. The objective of this paper is to describe the process whereby stakeholders (Fishers), were involved in directing and refining research questions to address their particular informational needs about mercury levels in Fish, potential risks, and methods to maintain health, by balancing the risks and benefits of Fish consumption. A range of stakeholders, mainly individual Fishers, Fishing organizations, and other scientists, were involved at nearly every stage. Community participants influenced many aspects of the design and implementation of the research, in the determination of which Fish species to sample, in the collection of the samples, and in the final analyses and synthesis, as well as the communication of results and implications of the research through their Fishing club publications, talks and gatherings. By involving the most interested and affected communities, the data and conclusions are relevant to their needs because the Fish examined were those they ate and wanted information about, and directly address concerns about the risk from consuming self-caught Fish. Although mercury levels in Fish presumed to be high in mercury are known, little information was available to the Fishermen on mercury levels in Fish that were low and thus provided little risk to their families. While community participatory research is more time-consuming and expensive than traditional scientific research, both the process and results are better scientifically in terms of community relevance.
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Selenium/mercury molar ratios in freshwater, marine, and commercial Fish from the USA: variation, risk, and health management
Reviews on environmental health, 2013Co-Authors: Joanna Burger, Michael GochfeldAbstract:Fish provide healthy protein as well as recreational and cultural benefits, but can also contain mercury (Hg), polychlorinated biphenyls (PCBs), and other contaminants that have adverse effects on humans and other organisms, particularly developing fetuses. Recently, some authors have suggested that a molar excess of selenium (Se) [e.g., selenium/mercury (Se/Hg) molar ratio >1] confers protection from Hg toxicity derived from Fish consumption. Herein, we review our studies of Hg and Se in freshwater, marine, and commercial Fish (mainly marine), examining the following: (1) whether and how Se/Hg molar ratios vary among species; (2) whether and how the molar ratios vary within species; (3) whether the molar ratios differ between freshwater and Saltwater Fish; (4) whether mean molar ratio values provide a reliable indication of potential risk to Fish consumers; and (5) whether mean Se/Hg molar ratios are sufficiently constant (e.g., low variation) to allow for use in risk assessment, risk management, or risk communication. In Saltwater Fish, mean Se/Hg molar ratios varied from 0.3 in mako shark to 68.1 in whiting. For freshwater Fish, the mean ratios varied from 0.68 in bowfin to 20.8 in black crappie. Commercial seafood (mainly Saltwater) showed great variation in ratios; shrimp and scallops had very high ratios. There was somewhat less variability in the ratios for freshwater Fish compared with the Fish from Saltwater, but there was no overall predictable difference in variation in Se/Hg molar ratios. For both Saltwater and freshwater Fish, some species with mean molar ratios above 1 had a significant proportion of individual Fish with molar ratios below 1. Overall, this indicates great variation in measures of central tendencies and in measures of dispersion. We suggest that relying on the Se/Hg molar ratio as a method of predicting reduced risk from Hg toxicity is problematic because of the great variation among and within Fish species, and the variation is not predictable because Hg varies by season, size of the Fish, and location of the Fish (which is not available for commercial Fish). With the high variation in ratios, and low predictability, the ratios are currently not useful for risk assessment and risk management, and vulnerable individuals cannot rely on mean Se/Hg molar ratios for protection from Hg toxicity.
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interspecific and intraspecific variation in selenium mercury molar ratios in Saltwater Fish from the aleutians potential protection on mercury toxicity by selenium
Science of The Total Environment, 2012Co-Authors: Joanna Burger, Michael Gochfeld, Christian Jeitner, Mark Donio, Taryn PittfieldAbstract:Abstract A number of factors affect the consumption risk from mercury in Fish, including mercury levels, seasonal patterns of mercury concentrations, human consumption patterns, and sensitive populations (e.g. pregnant women, fetuses, young children, and yet unknown genetic factors). Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for Saltwater Fish. We examine levels of mercury and selenium in several species of Fish and seabirds from the Aleutians (Alaska), determine selenium:mercury molar ratios, and examine species-specific and individual variation in the ratios as a means of exploring the use of the ratio in risk assessment and risk management. Variation among species was similar for mercury and selenium. There was significant interspecific and intraspecific variation in selenium:mercury molar ratios for Fish, and for birds. The mean selenium:mercury molar ratios for all Fish and bird species were above 1, meaning there was an excess of selenium relative to mercury. It has been suggested that an excess of selenium confers some protective advantage for salt water Fish, although the degree of excess necessary is unclear. The selenium:mercury molar ratio was significantly correlated negatively with total length for most Fish species, but not for dolly varden. Some individuals of Pacific cod, yellow irish lord, rock greenling, Pacific halibut, dolly varden, and to a lesser extent, flathead sole, had selenium:mercury ratios below 1. No bird muscle had an excess of mercury (ratio below 1), and only glaucous-winged gull and pigeon guillemot had ratios between 1 and 5. There was a great deal of variation in selenium:mercury molar ratios within Fish species, and within bird species, making it difficult and impractical to use these ratios in risk assessment or management, for Fish advisories, or for consumers, particularly given the difficulty of interpreting the ratios.
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selenium and mercury molar ratios in Saltwater Fish from new jersey individual and species variability complicate use in human health Fish consumption advisories
Environmental Research, 2012Co-Authors: Joanna Burger, Michael GochfeldAbstract:Balancing risk versus benefits to humans and other organisms from consuming Fish is a national concern in the USA, as well as in many other parts of the world. Protecting public health is both a federal and state responsibility, and states respond by issuing Fish consumption advisories, particularly for mercury. Recently it has been emphasized that the protective role of selenium against mercury toxicity depends on their molar ratios, which should be evaluated as an indication of selenium's protective capacity, and incorporated in risk assessments for Fish consumption. However, there is no single “protective” ratio agreed upon. In this paper we examine the selenium:mercury (Se:Hg) molar ratios in a wide range of Saltwater Fish caught and eaten by recreational Fishers along the New Jersey coast. We were particularly interested in interspecific and intraspecific variability, and whether the molar ratios were consistent within a species, allowing for its use in managing risk. The selenium–mercury molar ratio showed significant variation among and within Fish species. The molar ratio decreased with the size of the Fish species, decreased with the mercury levels, and within a Fish species, the selenium:mercury ratio decreased with Fish size. As an essential element, selenium undergoes some homeostatic regulation, but it is also highly toxic. Within species, mercury level tends to increase with size, accounting for the negative relationship between size and ratio. This variability may make it difficult to use the selenium:mercury molar ratio in risk assessment, risk management, and risk communication at this time, and more information is needed on how mercury and selenium actually interact and on the relationship between the molar ratios and health outcomes.
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locational differences in mercury and selenium levels in 19 species of Saltwater Fish from new jersey
Journal of Toxicology and Environmental Health, 2011Co-Authors: Joanna Burger, Christian Jeitner, Michael GochfeldAbstract:Individuals who Fish, and their families that ingest self-caught Fish, make decisions about where to Fish, what type of Fish to eat, and the quantity of Fish to eat. While federal and state agencies often issue consumption advisories for some Fish with high mercury (Hg) concentrations, advisories seldom provide the actual metal levels to the general public. There are few data for most Saltwater Fish, and even less information on variations in Hg levels in Fish within a state or geographical region. The objective of this study was to provide Hg concentrations from 19 species of Fish caught in different locations in New Jersey to (1) test the hypothesis that mean metal levels vary geographically, (2) provide this information to individuals who Fish these coastal waters, and (3) provide a range of values for risk assessors who deal with Saltwater Fish exposure in the Northeastern United States. Selenium (Se) was also examined because of its purported moderating effect on the toxicity of Hg. Hg levels showed ...
Antonio Lucacchini - One of the best experts on this subject based on the ideXlab platform.
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binding of the benzodiazepine ligand 3h ro 15 1788 to brain membrane of the Saltwater Fish mullus surmuletus
Neurochemistry International, 1997Co-Authors: Gino Giannaccini, Laura Betti, Massimo Correani, Marco Dini, Laura Giusti, Antonio LucacchiniAbstract:Abstract The distribution and the pharmacological properties of the binding of the benzodiazepine receptor antagonist [3H]-Ro 15–1788 (8-fluoro-3-carboethoxy-5,6-dihydro-5-methyl-6-oxo-4H imidazol [1,5-a] 1,4 benzodiazepine) were compared in some brain membranes of the Saltwater teleost Fish, Mullus surmuletus: only a single population of [3H]-Ro 15–1788 binding sites was detected. The binding was saturable and reversible with a high affinity, revealing a significant population of binding sites (Kd value of 2.1 ± 0.2 nM and Bmax value of 1400-900 fmol mg−1 of protein, depending on Fish length). The highest concentration of benzodiazepine recognition sites labelled with [3H]-Ro 15–1788 was present in the optic lobe and the olfactory bulb and the lowest concentration was found in the medulla oblongata, cerebellum and spinal cord. In order to explore behavioural selectivity as a consequence of multiple receptor subtypes, six benzodiazepine receptor ligands, flunitrazepam (5-(2-fluoro-phenyl)-1,3,dihydro-1-methyl-7-nitro-2H-1,4-benzodiazepine-2-one), alpidem, (N,N-dipropyl-6-chloro-2-(4-chlorophenyl) imidazo [1,2-a] pyridine-3-acetamide) zolpidem {N,N,6, trimethyl-2-(4-methyl-phenyl) imidazo [1,2-a] pyridine-3-acetamide hemitartrate}, methyl β carboline-3-carboxylate (βCCM), Ro 15–1788 and Ro 5–4864 (4′-chlorodiazepam), were tested in vitro by binding of [3H]-Ro 15–1788 to membrane preparations from various brain areas of Mullus surmuletus. Displacement studies showed a similar rank order of efficacy of various unlabelled ligands. In all regions of the brain and in the spinal cord, GABA potentiate [3H]-flunitrazepam binding in a similar order, suggesting that the BDZ recognition sites are part of the GABAA receptor structure. These results suggest that central-type benzodiazepine receptors are present in one class of benzodiazepine binding sites in the Saltwater teleost Fish brain of Mullus surmuletus (type I-like). Here we report initial evidence of homogeneity of subtypes of central benzodiazepine receptors in the spinal cord of the Saltwater teleost Fish, Mullus surmuletus.
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Binding of the benzodiazepine ligand [3H]-Ro 15–1788 to brain membrane of the Saltwater Fish Mullus surmuletus
Neurochemistry International, 1997Co-Authors: Gino Giannaccini, Laura Betti, Massimo Correani, Marco Dini, Laura Giusti, Antonio LucacchiniAbstract:Abstract The distribution and the pharmacological properties of the binding of the benzodiazepine receptor antagonist [3H]-Ro 15–1788 (8-fluoro-3-carboethoxy-5,6-dihydro-5-methyl-6-oxo-4H imidazol [1,5-a] 1,4 benzodiazepine) were compared in some brain membranes of the Saltwater teleost Fish, Mullus surmuletus: only a single population of [3H]-Ro 15–1788 binding sites was detected. The binding was saturable and reversible with a high affinity, revealing a significant population of binding sites (Kd value of 2.1 ± 0.2 nM and Bmax value of 1400-900 fmol mg−1 of protein, depending on Fish length). The highest concentration of benzodiazepine recognition sites labelled with [3H]-Ro 15–1788 was present in the optic lobe and the olfactory bulb and the lowest concentration was found in the medulla oblongata, cerebellum and spinal cord. In order to explore behavioural selectivity as a consequence of multiple receptor subtypes, six benzodiazepine receptor ligands, flunitrazepam (5-(2-fluoro-phenyl)-1,3,dihydro-1-methyl-7-nitro-2H-1,4-benzodiazepine-2-one), alpidem, (N,N-dipropyl-6-chloro-2-(4-chlorophenyl) imidazo [1,2-a] pyridine-3-acetamide) zolpidem {N,N,6, trimethyl-2-(4-methyl-phenyl) imidazo [1,2-a] pyridine-3-acetamide hemitartrate}, methyl β carboline-3-carboxylate (βCCM), Ro 15–1788 and Ro 5–4864 (4′-chlorodiazepam), were tested in vitro by binding of [3H]-Ro 15–1788 to membrane preparations from various brain areas of Mullus surmuletus. Displacement studies showed a similar rank order of efficacy of various unlabelled ligands. In all regions of the brain and in the spinal cord, GABA potentiate [3H]-flunitrazepam binding in a similar order, suggesting that the BDZ recognition sites are part of the GABAA receptor structure. These results suggest that central-type benzodiazepine receptors are present in one class of benzodiazepine binding sites in the Saltwater teleost Fish brain of Mullus surmuletus (type I-like). Here we report initial evidence of homogeneity of subtypes of central benzodiazepine receptors in the spinal cord of the Saltwater teleost Fish, Mullus surmuletus.
Masanori Yoshida - One of the best experts on this subject based on the ideXlab platform.
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nucleotide sequence of a major satellite dna element isolated from a Saltwater Fish sillago japonica
Molecular Biology Reports, 1996Co-Authors: Mikio Kato, Masanori YoshidaAbstract:A member of satellite repetitive DNA was isolated and sequenced from a Saltwater FishSillago japonica (Percoidei). This sequence consists of several oligo-dA/dT tracts and two inverted repeats which resemble each other. Dot blot hybridization analysis using a satellite DNA clone pSJ2 among the species in the suborder Percoidei revealed that the pSJ2 sequence was amplified at least after the family Sillaginidae had been derived.
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Nucleotide sequence of a major satellite DNA element isolated from a Saltwater FishSillago japonica
Molecular Biology Reports, 1995Co-Authors: Mikio Kato, Masanori YoshidaAbstract:A member of satellite repetitive DNA was isolated and sequenced from a Saltwater Fish Sillago japonica (Percoidei). This sequence consists of several oligo-dA/dT tracts and two inverted repeats which resemble each other. Dot blot hybridization analysis using a satellite DNA clone pSJ2 among the species in the suborder Percoidei revealed that the pSJ2 sequence was amplified at least after the family Sillaginidae had been derived.
Gino Giannaccini - One of the best experts on this subject based on the ideXlab platform.
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binding of the benzodiazepine ligand 3h ro 15 1788 to brain membrane of the Saltwater Fish mullus surmuletus
Neurochemistry International, 1997Co-Authors: Gino Giannaccini, Laura Betti, Massimo Correani, Marco Dini, Laura Giusti, Antonio LucacchiniAbstract:Abstract The distribution and the pharmacological properties of the binding of the benzodiazepine receptor antagonist [3H]-Ro 15–1788 (8-fluoro-3-carboethoxy-5,6-dihydro-5-methyl-6-oxo-4H imidazol [1,5-a] 1,4 benzodiazepine) were compared in some brain membranes of the Saltwater teleost Fish, Mullus surmuletus: only a single population of [3H]-Ro 15–1788 binding sites was detected. The binding was saturable and reversible with a high affinity, revealing a significant population of binding sites (Kd value of 2.1 ± 0.2 nM and Bmax value of 1400-900 fmol mg−1 of protein, depending on Fish length). The highest concentration of benzodiazepine recognition sites labelled with [3H]-Ro 15–1788 was present in the optic lobe and the olfactory bulb and the lowest concentration was found in the medulla oblongata, cerebellum and spinal cord. In order to explore behavioural selectivity as a consequence of multiple receptor subtypes, six benzodiazepine receptor ligands, flunitrazepam (5-(2-fluoro-phenyl)-1,3,dihydro-1-methyl-7-nitro-2H-1,4-benzodiazepine-2-one), alpidem, (N,N-dipropyl-6-chloro-2-(4-chlorophenyl) imidazo [1,2-a] pyridine-3-acetamide) zolpidem {N,N,6, trimethyl-2-(4-methyl-phenyl) imidazo [1,2-a] pyridine-3-acetamide hemitartrate}, methyl β carboline-3-carboxylate (βCCM), Ro 15–1788 and Ro 5–4864 (4′-chlorodiazepam), were tested in vitro by binding of [3H]-Ro 15–1788 to membrane preparations from various brain areas of Mullus surmuletus. Displacement studies showed a similar rank order of efficacy of various unlabelled ligands. In all regions of the brain and in the spinal cord, GABA potentiate [3H]-flunitrazepam binding in a similar order, suggesting that the BDZ recognition sites are part of the GABAA receptor structure. These results suggest that central-type benzodiazepine receptors are present in one class of benzodiazepine binding sites in the Saltwater teleost Fish brain of Mullus surmuletus (type I-like). Here we report initial evidence of homogeneity of subtypes of central benzodiazepine receptors in the spinal cord of the Saltwater teleost Fish, Mullus surmuletus.
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Binding of the benzodiazepine ligand [3H]-Ro 15–1788 to brain membrane of the Saltwater Fish Mullus surmuletus
Neurochemistry International, 1997Co-Authors: Gino Giannaccini, Laura Betti, Massimo Correani, Marco Dini, Laura Giusti, Antonio LucacchiniAbstract:Abstract The distribution and the pharmacological properties of the binding of the benzodiazepine receptor antagonist [3H]-Ro 15–1788 (8-fluoro-3-carboethoxy-5,6-dihydro-5-methyl-6-oxo-4H imidazol [1,5-a] 1,4 benzodiazepine) were compared in some brain membranes of the Saltwater teleost Fish, Mullus surmuletus: only a single population of [3H]-Ro 15–1788 binding sites was detected. The binding was saturable and reversible with a high affinity, revealing a significant population of binding sites (Kd value of 2.1 ± 0.2 nM and Bmax value of 1400-900 fmol mg−1 of protein, depending on Fish length). The highest concentration of benzodiazepine recognition sites labelled with [3H]-Ro 15–1788 was present in the optic lobe and the olfactory bulb and the lowest concentration was found in the medulla oblongata, cerebellum and spinal cord. In order to explore behavioural selectivity as a consequence of multiple receptor subtypes, six benzodiazepine receptor ligands, flunitrazepam (5-(2-fluoro-phenyl)-1,3,dihydro-1-methyl-7-nitro-2H-1,4-benzodiazepine-2-one), alpidem, (N,N-dipropyl-6-chloro-2-(4-chlorophenyl) imidazo [1,2-a] pyridine-3-acetamide) zolpidem {N,N,6, trimethyl-2-(4-methyl-phenyl) imidazo [1,2-a] pyridine-3-acetamide hemitartrate}, methyl β carboline-3-carboxylate (βCCM), Ro 15–1788 and Ro 5–4864 (4′-chlorodiazepam), were tested in vitro by binding of [3H]-Ro 15–1788 to membrane preparations from various brain areas of Mullus surmuletus. Displacement studies showed a similar rank order of efficacy of various unlabelled ligands. In all regions of the brain and in the spinal cord, GABA potentiate [3H]-flunitrazepam binding in a similar order, suggesting that the BDZ recognition sites are part of the GABAA receptor structure. These results suggest that central-type benzodiazepine receptors are present in one class of benzodiazepine binding sites in the Saltwater teleost Fish brain of Mullus surmuletus (type I-like). Here we report initial evidence of homogeneity of subtypes of central benzodiazepine receptors in the spinal cord of the Saltwater teleost Fish, Mullus surmuletus.
