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Screens were made for alcohol dehydrogenase (ADH) of the classical type (the MDR superfamily) in translations of human and other relevant genomes, corresponding to the organism types from which the enzyme was initially purified. Considerable multiplicities were detected in the dimeric enzymes from higher eukaryotes: seven forms in the human (plus three pseudogenes), all genes on chromosome 4, in the order class IV --> class Igamma --> class Ibeta --> class Ialpha --> class V --> class II --> class III, and eight forms in Arabidopsis thaliana (plus one pseudogene). These multiplicity patterns, and the species variability in the animal (human/mouse) and plant (Arabidopsis/pea) lines, suggest parallel but separate duplicatory events, giving rise to three families of dimeric MDR-ADH: class III, the animal non-class III, and the plant non-class III enzymes, with functions in formaldehyde elimination, in alcohol/aldehyde detoxication and in special pathways in higher eukaryotes. Multiplicity, although to a lesser extent, was also noted in tetrameric MDR-ADH, suggesting functional divergence between the dimeric and tetrameric enzymes. Combining these observations, at least five levels of divergence are reflected in the present ADH forms, corresponding to nodes at the SDR/MDR, the dimer/tetramer, the class III/non-class III, the class I/P, and the more recent class splits, each branch associated with separate functional patterns.  相似文献   

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Alcohol dehydrogenases (ADHs) of the MDR type (medium-chain dehydrogenases/reductases) have diverged into two evolutionary groups in eukaryotes: a set of 'constant' enzymes (class III) typical of basal enzymes, and a set of 'variable' enzymes (remaining classes) suggesting 'evolving' forms. The variable set has larger overall variability, different segment variability, and variability also in functional segments. Using a major aldehyde dehydrogenase (ALDH) from cod liver and fish ALDHs deduced from the draft genome sequence of Fugu rubripes (Japanese puffer fish), we found that ALDHs form more complex patterns than the ADHs. Nevertheless, ALDHs also group into 'constant' and 'variable' sets, have separate segment variabilities, and distinct functions. Betaine ALDH (class 9 ALDH) is 'constant,' has three segments of variability, all non-functional, and a limited fish/human divergence, reminiscent of the ADH class III pattern. Enzymatic properties of fish betaine ALDH were also determined. Although all ALDH patterns are still not known, overall patterns are related to those of ADH, and group separations may be distinguished. The results can be interpreted functionally, support ALDH isozyme distinctions, and assign properties to the multiplicities of the ADH and ALDH enzymes.  相似文献   

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Summary The technique of selective breeding has been employed to develop a number of mouse lines differing in genetic sensitivity to specific effects of ethanol. Genetic animal models for sensitivity to the hypnotic, thermoregulatory, excitatory, and dependence-producing effects of alcohol have been developed. These genetic animal models have been utilized in numerous studies to assess the bases for those genetic differences, and to determine the specific neurochemical and neurophysiological bases for ethanol's actions. Work with these lines has challenged some long-held beliefs about ethanol's mechanisms of action. For example, lines genetically sensitive to one effect of ethanol are not necessarily sensitive to others, which demonstrates that no single set of genes modulates all ethanol effects. LS mice, selected for sensitivity to ethanol anesthesia, are not similarly sensitive to all anesthetic drugs, which demonstrates that all such drugs cannot have a common mechanism of action. On the other hand, WSP mice, genetically susceptible to the development of severe ethanol withdrawal, show a similar predisposition to diazepam and phenobarbital withdrawal, which suggests that there may be a common set of genes underlying drug dependentcies. Studies with these models have also revealed important new directions for future mechanism-oriented research. Several studies implicate brain gamma-aminobutyric acid and dopamine systems as potentially important mediators of susceptibility to alcohol intoxication. The stability of the genetic animal models across laboratories and generations will continue to increase their power as analytic tools.  相似文献   

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Selected mouse lines, alcohol and behavior   总被引:3,自引:0,他引:3  
The technique of selective breeding has been employed to develop a number of mouse lines differing in genetic sensitivity to specific effects of ethanol. Genetic animal models for sensitivity to the hypnotic, thermoregulatory, excitatory, and dependence-producing effects of alcohol have been developed. These genetic animal models have been utilized in numerous studies to assess the bases for those genetic differences, and to determine the specific neurochemical and neurophysiological bases for ethanol's actions. Work with these lines has challenged some long-held beliefs about ethanol's mechanisms of action. For example, lines genetically sensitive to one effect of ethanol are not necessarily sensitive to others, which demonstrates that no single set of genes modulates all ethanol effects. LS mice, selected for sensitivity to ethanol anesthesia, are not similarly sensitive to all anesthetic drugs, which demonstrates that all such drugs cannot have a common mechanism of action. On the other hand, WSP mice, genetically susceptible to the development of severe ethanol withdrawal, show a similar predisposition to diazepam and phenobarbital withdrawal, which suggests that there may be a common set of genes underlying drug dependencies. Studies with these models have also revealed important new directions for future mechanism-oriented research. Several studies implicate brain gamma-aminobutyric acid and dopamine systems as potentially important mediators of susceptibility to alcohol intoxication. The stability of the genetic animal models across laboratories and generations will continue to increase their power as analytic tools.  相似文献   

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Zusammenfassung Die Ergebnisse der bisherigen Untersuchungen zum zytochemischen Nachweis verschiedener Dehydrogenasen und Oxydasen in den Zellen von Pilzen (Neurospora crassa, Oospora lactis, Saccharomyces cerevisiae u.a.) werden beschrieben.  相似文献   

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Zusammenfassung Verschiedene Dehydrogenasen, die physiologischerweise nur in der Leber vorkommen, wurden bei Virushepatitis der Mäuse in fortgeschrittenem Stadium auch im Blut gefunden.  相似文献   

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Antiquitin is a member of the aldehyde dehydrogenase superfamily. Sequence analyses indicate that the protein is highly conserved from plants to animals. The plant antiquitins are generally believed to play a role in osmoregulation and/or detoxification. The physiological functions of animal antiquitins remain largely elusive, their involvement in a number of human diseases has been implicated. Received 28 February 2006; received after revision 13 July 2006; accepted 31 August 2006  相似文献   

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Resumen Se estudiaron las actividades de glucosa-6-fosfato dehidrogenasa y 6-fosfogluconato dehidrogenasa en hígado y tejido adiposo de ratas preñadas, al día 19 de gestación, alimentadas y en ayunas de 48 h, relacionando los resultados obtenidos con la velocidad de síntesis de ácidos grasos en el tejido adiposo de los mismos animales.

This study was carried out at the Section of Endocrinology and Metabolism, Departments of Medicine and Biochemistry, Northwestern University Medical School, Chicago, Ill, USA. The authors are indepted to Dr.N. Freinkel for his encouragement. This work was supported in part by Research Grant AM-10699 and Training Grant AM-05071 from the National Institute of Arthritis and Metabolic Diseases, U.S. Public Health Service, Bethesda, Maryland, USA.  相似文献   

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Zusammenfassung Es wird nachgewiesen, dass die Aktivität von Succinat Dehydrogenase und von Pyruvat Dehydrogenase in Extrakten normaler und denervierter Muskulatur durch Ca++ im pH-Bereich von 5,8 bis 7,8 in verschiedenem Ausmass erhöht bzw. erniedrigt wird.  相似文献   

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Zusammenfassung Die Aktivitäten der Isocitrat- und Glukose-6-P-Dehydrogenasen erreichen in Kakteen (Nopalea dejecta) zu verschiedenen Tageszeiten ihr Maximum.  相似文献   

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Summary Two classes of amine-aldehyde adducts, the tetrahydroisoquinoline (TIQ) and beta-carboline (THBC) compounds, have been implicated in the mechanism in the brain underlying the addictive drinking of alcohol. One part of this review focuses on the large amount of evidence unequivocally demonstrating not only the corporeal synthesis of the TIQs and THBCs but their sequestration in brain tissue as well. Experimental studies published recently have revealed that exposure to alcohol enhances markedly the endogenous formation of condensation products. Apart from their multiple neuropharmacological actions, certain adducts when delivered directly into the brain of either the rat or monkey, to circumvent the brain's blood-barrier system, can evoke an intense and dose-dependent increase in the voluntary drinking of solutions of alcohol even in noxious concentrations. That the abnormal intake of alcohol is related functionally to opioid receptors in the brain is likely on the basis of several dinstinct lines of evidence which include: the attenuation of alcohol drinking by opioid receptor antagoists; binding of a TIQ to opiate receptors in the brain; and marked differences in enkephalin values in animals genetically predisposed to the ingestion of alcohol. Finally, it is proposed that the dopaminergic reward pathways which traverse the meso-limbic-forebrain systems of the brain more than likely constitute an integrative anatomical substrate for the adduct-opioid cascade of neuronal events which promote and sustain the aberrant drinking of alcohol.  相似文献   

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R D Myers 《Experientia》1989,45(5):436-443
Two classes of amine-aldehyde adducts, the tetrahydroisoquinoline (TIQ) and beta-carboline (THBC) compounds, have been implicated in the mechanism in the brain underlying the addictive drinking of alcohol. One part of this review focuses on the large amount of evidence unequivocally demonstrating not only the corporeal synthesis of the TIQs and THBCs but their sequestration in brain tissue as well. Experimental studies published recently have revealed that exposure to alcohol enhances markedly the endogenous formation of condensation products. Apart from their multiple neuropharmacological actions, certain adducts when delivered directly into the brain of either the rat or monkey, to circumvent the brain's blood-barrier system, can evoke an intense and dose-dependent increase in the voluntary drinking of solutions of alcohol even in noxious concentrations. That the abnormal intake of alcohol is related functionally to opioid receptors in the brain is likely on the basis of several distinct lines of evidence which include: the attenuation of alcohol drinking by opioid receptor antagonists; binding of a TIQ to opiate receptors in the brain; and marked differences in enkephalin values in animals genetically predisposed to the ingestion of alcohol. Finally, it is proposed that the dopaminergic reward pathways which traverse the meso-limbic-forebrain systems of the brain more than likely constitute an integrative anatomical substrate for the adduct-opioid cascade of neuronal events which promote and sustain the aberrant drinking of alcohol.  相似文献   

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Riassunto In pazienti affetti da artrite reumatoide viene iniettato cortisone acetato, idrocortisone acetato, o idrocortisone, nel cavo sinoviale artritico.La durata del riassorbimento di questi 17-idrossicorticoidi; la loro distribuzione nelle cellule e nel fluido articolare e nelle cellule del rivestimento sinoviale; le andamento del processo idrolitico dei composti acetati, studiati con mezzi chimici e cromatografici, si prestano a commenti utili ad interpretare la maggiore efficacia locale dell'idrocortisone.

Supported by a grant from the Helen Augusta Parkhill Foundation.—Communication at the 8th International Congress of Rheumatic Diseases, Geneva, August 1953.  相似文献   

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