RESUMO
In humans the release of growth hormone (GH) elicited by dopamine (DA) and DA agonists may represent a reliable model to assess change in sensitivity of DA receptors. We now report that in chronic alcoholics, 4-7 days after the suspension of alcohol consumption, the increase of GH response to DA infusion was higher than that seen in non alcoholic volunteers. The specificity of this GH response to DA administration was demonstrated by the use of domperidone, a novel peripheral antagonist of DA receptors. These results suggest the development of hyper-responsiveness of DA receptors involved in the control of GH secretion in chronic alcoholics during the later phases of the "withdrawal syndrome".
Assuntos
Dopamina/fisiologia , Etanol/efeitos adversos , Hormônio do Crescimento/metabolismo , Receptores Dopaminérgicos/fisiologia , Síndrome de Abstinência a Substâncias/fisiopatologia , Adulto , Domperidona/farmacologia , Feminino , Humanos , Masculino , Estimulação Química , Fatores de TempoRESUMO
Sediments collected in Tiber river and in its main tributary water courses within the urban area of Rome were tested for mutagenicity by means of Vicia faba root tips micronucleus (MN) test. Representative samples were scored for micronucleus generating events (chromosome/chromatid loss and fragments) too. Sediments were assayed for content of the thirteen most important chemicals of polycyclic aromatic hydrocarbon (PAH) group and for some heavy metal ions (Cd, Cr, Cu, Ni, Pb, Zn). Samples were collected in four tributary rivers (Prima Porta, Acqua Traversa, Aniene and Magliana) just before their confluence with Tiber river and at different stations along the Tiber river itself upstream and downstream the sites of confluence of the sampled tributaries. All samples were collected in July 1992. An alarming level of mutagenicity was reached in most of the tested stations, with an effect comparable to an X-rays exposure up to 0.4 Gy. Chemical analysis showed that the total amount of identified PAHs ranged from 4.5 to 625.2 ng/g of dry matrix in the different stations and the total amount of heavy metals ranged from 130 to 570 ppm. Tiber mutagenicity is likely to be mainly due to local factors such as the confluence of a small polluted tributary rather than to large scale effect due to an upstream-downstream relationship.
Assuntos
Sedimentos Geológicos/análise , Metais Pesados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes da Água/análise , Poluição da Água , Cádmio/análise , Cromatografia Líquida de Alta Pressão , Cromo/análise , Cobre/análise , Fabaceae/química , Água Doce , Chumbo/análise , Modelos Lineares , Metais Pesados/toxicidade , Testes para Micronúcleos , Níquel/análise , Plantas Medicinais , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Análise de Regressão , Cidade de Roma , Espectrofotometria Atômica , Poluentes da Água/toxicidade , Zinco/análiseRESUMO
An inquiry, by the "Duplicate Portion" technique, has been made to estimate the daily assimilation of cadmium in various collectivities of Rome, representative of different economical-social and sanitary realities. At this regard, 132 complete meals, coming from a hospital canteen, a nursing home for old people, a big company, a community of students and an agricultural firm, have been examined. The sample has been mineralized to white ashes and analyzed in spectrophotometry at A.A. with a little oven of graphite. The data about cadmium assimilation, that we have obtained, are included between 12 and 25 micrograms/day and they are placed at medium-low levels, if we compare then with an assimilation of 15-60 micrograms/day, carried from studies on various populations. No daily data exceeded the limit of tolerability of 57-71 micrograms/day suggested from the W.H.O. Our data, coming the point, do not indicate a particular situation of danger for the groups of population we have studied.
Assuntos
Cádmio/análise , Contaminação de Alimentos/análise , Humanos , Cidade de RomaRESUMO
The use of Tenax GC for the extraction of organic micro-pollutants such as pesticides and polynuclear aromatic hydrocarbons from water has been studied. In the absence of other contaminants and under conditions standardized at the time as optimal, the recovery of such substances is, on average, over 90%, both for the organochlorine and organophosphorus pesticides and for polynuclear aromatic hydrocarbons. Research into the effectiveness of extraction with Tenax from natural waters and water artificially contaminated with surfactants, fats and oils etc., in the laboratory is now being carried out.
Assuntos
Praguicidas/análise , Compostos Policíclicos/análise , Poluentes da Água/análise , Cromatografia , Métodos , Éteres Fenílicos , PolímerosRESUMO
In a uniform group of 30 patients the A. have assessed the incidence of lower serum K+ and Mg++ concentrations on the probability of arrhythmias onset in the acute phase of myocardial infarction. The study shows that lower K+ and Mg++ levels significantly influence only the onset of ventricular tachycardia and monofocal PVC.
Assuntos
Arritmias Cardíacas/fisiopatologia , Hipopotassemia/fisiopatologia , Deficiência de Magnésio/fisiopatologia , Infarto do Miocárdio/complicações , Adulto , Idoso , Arritmias Cardíacas/sangue , Arritmias Cardíacas/etiologia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Fatores de RiscoRESUMO
The occlusion of bile duct reduced the microsomal cytochrome P-450 activity in the liver of rats. However, the effects of the inducer drug, phenobarbital, were not abolished.
Assuntos
Colestase/metabolismo , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Bilirrubina/sangue , Colestase/sangue , Sistema Enzimático do Citocromo P-450/metabolismo , Interações Medicamentosas , Indução Enzimática , Feminino , L-Lactato Desidrogenase/sangue , Masculino , Microssomos Hepáticos/metabolismo , Pentobarbital/farmacologia , Fenobarbital/farmacologia , RatosRESUMO
We measured glutathione and cysteine concentrations in erythrocytes of chronic alcohol misusers with (20 subjects) and without liver cirrhosis (20 subjects). Glutathione levels were decreased, whereas those of cysteine were increased in all patients. Parenteral treatment with S-adenosylmethionine (SAME); (2 g daily in 250 ml 0.15 M NaCl for 15 days) corrected the erythrocyte thiol alterations. We conclude that parenteral treatment with SAME affects the metabolism of SH compounds in erythrocytes of alcoholic patients.
Assuntos
Alcoolismo/reabilitação , Cisteína/sangue , Eritrócitos/efeitos dos fármacos , Glutationa/sangue , Cirrose Hepática Alcoólica/reabilitação , S-Adenosilmetionina/administração & dosagem , Adulto , Alcoolismo/sangue , Eritrócitos/metabolismo , Humanos , Cirrose Hepática Alcoólica/sangue , Testes de Função Hepática , Masculino , Pessoa de Meia-IdadeRESUMO
This study evaluated the regional distribution of sulfhydryl compounds in the human gastric mucosa and the effect of ethanol on gastric sulfhydryl tissue levels. Total sulfhydryl, glutathione, and cysteine and their oxidized forms were measured in biopsy specimens taken from the gastric body and antrum of 22 healthy volunteers. Total sulfhydryl and glutathione contents of the body of the stomach were significantly higher than those of the antrum. In contrast, cysteine concentration was higher in the gastric antrum than in the body. No difference was found in the levels of oxidized sulfhydryls between the gastric body and antrum. The effect of acute administration of ethanol on gastric sulfhydryl content was studied in nine subjects. Ethanol caused gross mucosal damage and lowered the concentration of sulfhydryl compounds in both the body and the antrum. In 10 chronic alcoholics total sulfhydryl and glutathione, but not cysteine, were markedly decreased in the gastric body but not in the antrum as compared with nonalcoholic controls. In conclusion, 1) the human gastric body contains significantly higher tissue levels of total sulfhydryls and glutathione and lower concentrations of cysteine than the antrum; 2) ethanol in a damaging concentration significantly decreases gastric tissue levels of sulfhydryl compounds; and 3) chronic ethanol intake lowers total sulfhydryl and glutathione tissue levels in the gastric body.
Assuntos
Etanol/farmacologia , Mucosa Gástrica/química , Proteínas/análise , Compostos de Sulfidrila/análise , Adulto , Cisteína/análise , Feminino , Mucosa Gástrica/efeitos dos fármacos , Glutationa/análise , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The oxidation of ethanol and acetaldehyde enhances the production of various free radicals involved in membrane lipoperoxidation, and decreases glutathione levels. AIMS: We evaluated the effects of acute and chronic ethanol use in vivo, with or without the administration of S-adenosyl-methionine (SAME, 2 g I.v.), and the effects of ethanol and acetaldehyde in vitro, on the erythrocyte levels of malonyldialdehyde and glutathione, and of its principal synthesizing enzymes, gamma-glutamyl-cysteine-synthetase and glutathione-synthetase. METHODS: Twelve healthy volunteers (age range 26-44 years, median 32 years) and 20 chronic alcohol abusers without liver disease (age range 26-57 years, median 44 years) were studied. Malonyldialdehyde was evaluated by thiobarbituric acid; glutathione and its enzymes by high performance liquid chromatography using a fluorescent detector. RESULTS: In the healthy subjects, an acute load of ethanol induced a significant decrease in plasma levels of glutathione, which was inhibited by the infusion of S-adenosyl-methionine. In the erythrocytes of alcoholic patients, glutathione and glutathione-synthetase were decreased while malonyldialdehyde was increased. In vitro, acetaldehyde did not affect either the glutathione or the glutathione-related enzyme levels. CONCLUSIONS: Our data suggest that the alterations in glutathione metabolism in the erythrocytes of alcoholics may be due principally to the production of free radicals, as supported by the high levels of malonyldialdehyde observed.
Assuntos
Alcoolismo/metabolismo , Etanol/metabolismo , Glutationa/metabolismo , Hepatopatias Alcoólicas/metabolismo , Acetaldeído/sangue , Acetaldeído/metabolismo , Doença Aguda , Adulto , Intoxicação Alcoólica/sangue , Intoxicação Alcoólica/metabolismo , Alcoolismo/sangue , Doença Crônica , Eritrócitos/metabolismo , Etanol/farmacologia , Radicais Livres/metabolismo , Glutationa/sangue , Humanos , Peroxidação de Lipídeos , Hepatopatias Alcoólicas/sangue , Masculino , Malondialdeído/sangue , Malondialdeído/metabolismoRESUMO
UNLABELLED: Alpha-gluthathione-S-transferases (alpha-GSTs) are enzymes involved in the cellular detoxifying processes; elevated circulating alpha-GSTs activity is considered to be an early index of liver damage. Glutathione (GSH) is the substrate for alpha-GST action. THE AIMS OF OUR STUDY WERE: (1) to evaluate plasma GSH levels and alpha-GST activity in chronic alcohol abusers with or without liver cirrhosis; (2) to define the relationship between these two biochemical parameters; (3) to establish their clinical relevance in patients with alcohol abuse and/or liver damage. We studied 69 subjects (18 healthy subjects and 51 chronic alcohol abusers: 29 without liver cirrhosis and 22 with). Plasma alpha-GST activity was determined on baseline samples and every following day for a total of 10 days in five alcoholics by HEPKIT (Alpha-Biotech, Biotrin International, Dublin, Ireland). GSH was determined on all subjects' baseline samples by fluorescent high-performance liquid chromatography. Alcohol intake was evaluated in all patients by determining blood-alcohol concentrations. Significant increases in plasma alpha-GSTs were observed in 9/29 (31%) alcoholics and 3/22 (13.6%) cirrhotics irrespective of their alcohol intake. GSH was significantly lower than normal values (P < 0.001) in all alcoholics with or without cirrhosis (controls 10.4 +/- 4.8; alcoholics without cirrhosis 3.9 +/- 1.4; alcoholics with cirrhosis 3.3 +/- 1.6). No correlation was observed between plasma alpha-GST and GSH levels. Our data indicate that: (1) alpha-GST activity does not correlate with GSH levels in the plasma; (2) alpha-GSTs do not have clinical relevance as markers of recent alcohol intake; (3) in cirrhotics, alpha-GST does not provide more information than other liver function tests. However, plasma alpha-GST determination may be useful in selecting a subgroup of alcoholics in whom routine biochemical markers of liver damage are within reference ranges.