RESUMO
OBJECTIVES: The aim was to study the association between venous disorders and leg symptoms in the population based cross sectional Bonn Vein Study 1 (BVS1). METHODS: A total of 1,350 men and 1,722 women aged 18-79 years were enrolled into BVS1. Chronic venous insufficiency (CVI), varicose veins (VVs), and clinical classes (C-classes/CEAP [Clinical, Etiological, Anatomical, and Pathophysiological]) were determined by clinical and duplex investigation. Leg symptoms (heaviness, tightness, swelling, pain after standing or sitting, pain while walking, muscle cramps, itching, and restless legs) were assessed in a standardized interview. For 2,624 subjects (48.7% male) with complete information on venous disorders, relevant characteristics and information on at least one leg symptom, multivariate logistic regression analysis was performed. RESULTS: More women (929/63.0%) reported at least one leg symptom within the last 4 weeks than men (560/48.7%). Prevalence of reported symptoms increased with age (45.4% of the 18-29 year olds, 73.9% of the 70-79 year olds). Leg symptoms were more frequent in obese and underweight subjects. As confirmed by clinical and duplex examination 22.6% had VV and 15.8% had CVI. VV (OR: 1.4; CI: 1.1-1.7) and CVI (OR: 1.8; CI: 1.3-2.3) were significantly associated with reporting at least one leg symptom. In particular, there was a positive association of VV and CVI with itching, feeling of heaviness, tightness, swelling, and pain after standing or sitting. C2-C6 showed a statistically significant association with feeling of heaviness, tightness, swelling, and itching, while for pain on walking and muscle cramps this was shifted towards C classes C3-C6 and C3-C4, respectively. CONCLUSIONS: Venous disorders show significant associations with several leg symptoms. Itching, feeling of heaviness, or tightness seem to be more closely related than other symptoms. The associations between C classes and symptoms seem to be restricted to classes C2 or higher.
Assuntos
Extremidade Inferior/irrigação sanguínea , Varizes/epidemiologia , Insuficiência Venosa/epidemiologia , Adolescente , Adulto , Idoso , Doença Crônica , Comorbidade , Estudos Transversais , Feminino , Alemanha/epidemiologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Medição da Dor , Prevalência , Prognóstico , Fatores de Risco , Fatores de Tempo , Ultrassonografia Doppler Dupla , Varizes/diagnóstico , Varizes/fisiopatologia , Insuficiência Venosa/diagnóstico , Insuficiência Venosa/fisiopatologia , Adulto JovemRESUMO
In the mouse uterus, lactoferrin is a major estrogen-inducible uterine secretory protein, and its expression correlates directly with the period of peak epithelial cell proliferation. In this study, we examine the expression of lactoferrin mRNA and protein in human endometrium, endometrial hyperplasias, and adenocarcinomas using immunohistochemistry, Western immunoblotting, and Northern and in situ RNA hybridization techniques. Our results reveal that lactoferrin is expressed in normal cycling endometrium by a restricted number of glandular epithelial cells located deep in the zona basalis. Two thirds (8 of 12) of the endometrial adenocarcinomas examined overexpress lactoferrin. This tumor-associated increase in lactoferrin expression includes an elevation in the mRNA and protein of individual cells and an increase in the number of cells expressing the protein. In comparison, only 1 of the 10 endometrial hyperplasia specimens examined demonstrates an increase in lactoferrin. We also observe distinct cytoplasmic and nuclear immunostaining patterns under different fixation conditions in both normal and malignant epithelial cells, similar to those previously reported in the mouse reproductive tract. Serial sections of malignant specimens show a good correlation between the localization of lactoferrin mRNA and protein in individual epithelial cells by in situ RNA hybridization and immunohistochemistry. Although the degree of lactoferrin expression in the adenocarcinomas did not correlate with the tumor stage, grade, or depth of invasion in these 12 patients, there was a striking inverse correlation between the presence of progesterone receptors and lactoferrin in all 8 lactoferrin-positive adenocarcinomas. In summary, lactoferrin is expressed in a region of normal endometrium known as the zona basalis which is not shed with menstruation and is frequently overexpressed by progesterone receptor-negative cells in endometrial adenocarcinomas.
Assuntos
Transformação Celular Neoplásica/genética , Neoplasias do Endométrio/patologia , Endométrio/metabolismo , Endométrio/patologia , Lactoferrina/biossíntese , Lactoferrina/genética , RNA Mensageiro/análise , Adenocarcinoma/química , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adulto , Idoso , Northern Blotting , Hiperplasia Endometrial/metabolismo , Hiperplasia Endometrial/patologia , Neoplasias do Endométrio/química , Neoplasias do Endométrio/metabolismo , Endométrio/química , Feminino , Humanos , Imuno-Histoquímica , Hibridização In Situ , Antígeno Ki-67 , Pessoa de Meia-Idade , Proteínas de Neoplasias/análise , Compostos de Nitrosoureia/análise , Proteínas Nucleares/análise , Fenótipo , RNA Mensageiro/genética , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Neoplasias Uterinas/química , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patologiaRESUMO
The electrochemical oxidation of a number of N-methylated uric acids at the pyrolytic graphite and gold electrodes has been compared to their enzymic oxidation with type VIII peroxidase and H2O2. Spectral, electroanalytical and kinetic evidence supports the conclusion that for all compounds the electrochemical and enzymic reactions proceed by identical mechanisms.
Assuntos
Ácido Úrico/análogos & derivados , Eletroquímica , Peroxidase do Rábano Silvestre , Cinética , Oxirredução , Espectrofotometria UltravioletaRESUMO
Lactoferrin (LTF), an iron-binding glycoprotein present in most exocrine secretions and in the secondary granules of polymorphonuclear leucocytes (PMN), is regulated by estrogen in the mouse reproductive tract. We investigated the expression of LTF mRNA and protein during the natural estrous cycle to increase our understanding of how this uterine secretory protein is regulated under physiological conditions. There was a positive correlation between LTF mRNA expression in the genital tract and serum estradiol (E2) concentrations. When E2 peaked in proestrus, LTF mRNA and protein were expressed in the uterus; however, during metestrus, when both E2 and progesterone levels were high, LTF mRNA was expressed, while LTF protein was decreasing. LTF protein expression may be hindered by progesterone or some other local factor in the endometrial epithelium after ovulation. Immunohistochemistry demonstrated two distinct staining patterns for LTF in the vaginal and endometrial epithelium. In one staining pattern, the colorimetric reaction was noted over the cytoplasm, and in the other, the nuclear region stained more intensely. This suggests the possibility that in addition to its known role as a secretory protein, LTF may be transported to the nucleus, serving an autocrine role. Our results also indicated that LTF protein is a useful marker for tracking PMN. Nonproliferating epithelial cells in the vagina and endometrium may synthesize chemotactic and/or adhesion molecules for PMN.
Assuntos
Endométrio/fisiologia , Estradiol/sangue , Estro/fisiologia , Tubas Uterinas/fisiologia , Lactoferrina/biossíntese , Progesterona/sangue , Útero/fisiologia , Vagina/fisiologia , Animais , DNA/biossíntese , Replicação do DNA , Epitélio/fisiologia , Tubas Uterinas/citologia , Feminino , Imuno-Histoquímica , Lactoferrina/análise , Lactoferrina/genética , Metestro , Camundongos , Camundongos Endogâmicos , Sondas RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Timidina/metabolismo , Vagina/citologiaRESUMO
The indolic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) has been widely speculated to express its neurodegenerative effects as a result of intraneuronol autoxidation. Until recently, it was believed that autoxidation led to reactive electrophilic quinone imine species which alkylated neuronal membrane proteins and that byproducts of the autoxidation reaction were cytotoxic reduced-oxygen species. This study reveals that at physiological pH carbanions of 5,7-DHT act as the primary electron-donor species to yield C(4)- and C(6)-centered free radical superoxide complexes in a 1:2 ratio. The C(4)-centered complex reacts to yield, ultimately, 5-hydroxytryptamine-4,7-dione which has been shown to be a significantly more powerful neurotoxin than 5,7-DHT. The C(6)-centered radical superoxide complexes react to give 6,6'-bis(5-hydroxytryptamine-4,7-dione). It is likely that the latter reaction yields O2.- as a cytotoxic byproduct.
Assuntos
5,7-Di-Hidroxitriptamina , Di-Hidroxitriptaminas , Neurotoxinas , Fenômenos Químicos , Físico-Química , Cromatografia Líquida de Alta Pressão , Oxirredução , Espectrofotometria UltravioletaRESUMO
The electrochemical oxidation of 5-hydroxytryptamine (5-HT) in acidic solution proceeds through a minor route leading first to 5,7-dihydroxytryptamine (5,7-DHT) then to 4,5,7-trihydroxytryptamine and finally to 5-hydroxytryptamine-4,7-dione. The latter compound is a major electrochemical oxidation product of 5,7-DHT at pH 2 and 7 and a major autoxidation product at pH greater than or equal to 6. Preliminary biological results indicate that 5-hydroxytryptamine-4,7-dione is a more potent central nervous system toxin than 5,7-DHT. These results show for the first time a chemical pathway from 5-HT to 5,7-DHT and suggest possible minor metabolic oxidative pathways for the neurotransmitter 5-HT to at least two powerful neurotoxins.
Assuntos
5,7-Di-Hidroxitriptamina , Di-Hidroxitriptaminas , Sistema Nervoso/efeitos dos fármacos , Serotonina , 5,6-Di-Hidroxitriptamina/toxicidade , 5,7-Di-Hidroxitriptamina/toxicidade , Animais , Cromatografia Líquida , Di-Hidroxitriptaminas/toxicidade , Concentração de Íons de Hidrogênio , Dose Letal Mediana , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas , Camundongos , Oxirredução , Espectrofotometria InfravermelhoRESUMO
Peroxidase (EC 1.11.1.7)/H2O2, ceruloplasmin (human type X)/O2, and tyrosinase (EC 1.14.18.1)/O2 all oxidized the indolic neurotransmitter 5-hydroxytryptamine (5-HT) in the physiological pH domain. Peroxidase/H2O2 oxidized 5-HT at pH values down to about 2.5. All oxidation reactions generated complex mixtures of products which included at least one known neurotoxin, tryptamine-4,5-dione. In general, the enzymatic oxidation pathways paralleled the in vitro electrochemical oxidation of 5-HT which has permitted suggestions to be made concerning the probable mechanisms of the enzyme-mediated reactions.
Assuntos
Ceruloplasmina/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Peroxidases/metabolismo , Serotonina/metabolismo , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Oxirredução , Serotonina/análogos & derivados , Serotonina/químicaRESUMO
Tryptamine-4,5-dione (Compound 1) is an in vitro oxidation product of 5-hydroxytryptamine (5-HT). Recent evidence has suggested that aberrant oxidations of 5-HT occur in the central nervous system of individuals with Alzheimer's disease (AD). In the event that Compound 1 is formed as a result of oxidation of 5-HT within serotonergic nerve terminals or axons, it would be expected to be rapidly conjugated by intraneuronal glutathione (GSH) to give 7-S-glutathionyl-tryptamine-4,5-dione (Compound 2). When injected into the brains of laboratory mice, Compound 2 was lethal (LD50 = 21 micrograms) and evoked hyperactivity for the first 30 min following drug administration. Particularly during this hyperactive phase Compound 2 caused a statistically significant decrease in whole brain levels of norepinephrine and 5-HT. Levels of dopamine were also decreased while whole brain concentrations of its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, were increased significantly. In the presence of GSH, NADPH and ascorbic acid, Compound 2 redox cycled in reactions that catalyzed the oxidation of these cellular reductants by molecular oxygen and formed H2O2 as a byproduct. Compound 2 also reacted with molar excesses of GSH to form more structurally complex glutathionyl conjugates. Several of these conjugates have been isolated and their structures determined using spectroscopic methods. It is conceivable that one or more of these conjugates might serve as analytical markers in a search for evidence in support of the hypothesis that aberrant oxidations of 5-HT occur in the Alzheimer brain. The redox cycling properties of Compound 2 and its facile reactions with cellular nucleophiles such as GSH may represent mechanisms that contribute to the toxicity of this drug.
Assuntos
Química Encefálica , Glutationa/análogos & derivados , Serotonina/metabolismo , Triptaminas/metabolismo , Acetilcolina/metabolismo , Doença de Alzheimer/metabolismo , Animais , Dopamina/metabolismo , Glutationa/síntese química , Glutationa/metabolismo , Glutationa/farmacologia , Masculino , Camundongos , Norepinefrina/metabolismo , Oxirredução , Consumo de Oxigênio/efeitos dos fármacos , Serotonina/análogos & derivados , Triptaminas/síntese química , Triptaminas/farmacologiaRESUMO
Guinea pigs, 250-350 g body weight, both sexes, were injected with 5X10(8.5) EID50 NDV (Radom strain) intracardially and intraperitoneally simultaneously. The animals were bled by cardiac puncture 0, 3, 6, 12, 24 and 48 hours after injection. After virus inactivation, serum interferon titration was performed in cultures of guinea pig embryo kidney cells with 50 percent plaque inhibition test using VSV. The highest interferon titer (64 u./ml) was found after 6 hours of inductor injection. Interferon titer decreased quickly and after 12 hours it was lower than 16 u./ml. Guinea pig serum interferon induced by NDV was resistant to pH 2 and 56 degrees C during 1 hour. Interferon was inactivated by trypsin. The decribed interferon did not protect heterologous species cells (swine) against Teschen Disease Virus infection. Other properties of this interferon are being studied.
Assuntos
Indutores de Interferon , Interferons/fisiologia , Animais , Feminino , Cobaias , Injeções Intraperitoneais , Masculino , Miocárdio , Vírus da Doença de NewcastleRESUMO
An important product of electrochemical oxidation of 5-hydroxytryptamine (5-HT) in acid solution is the purple compound tryptamine-4,5-dione (6). However, any attempt to concentrate a solution containing 6 causes it to disappear. The most important reaction of 6 is dimerization to give another purple compound 7,7'-bi-(5-hydroxytryptamine-4-one). Dione 6 can also apparently react with 2,4'-bi-5-hydroxytryptamine to give the trimer 4-[7'-(tryptamine-4,5-dione)]-2,4''-bi-5-hydroxytryptamine. Finally, 6 and other oxidation products of 5-HT react during the concentration step to yield what appears to be a trimer or perhaps a higher oligomer. This oligomer has not been identified, but it has been shown to decompose to give, in part, the neurotoxin 5-hydroxytryptamine-4,7-dione.
Assuntos
Indolquinonas , Serotonina/análise , Fenômenos Químicos , Química , Eletroquímica , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Oxirredução , Serotonina/análogos & derivados , Espectrofotometria UltravioletaRESUMO
Ethanol is metabolized in the brain by catalase/H2O2 to yield acetaldehyde and by an ethanol-inducible form of cytochrome P450 (P450 IIE1) in a reaction that yields oxygen radicals. Within the cytoplasm of serotonergic axon terminals these metabolic pathways together provide conditions for the endogenous synthesis of 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline (1), by reaction of acetaldehyde with unbound 5-hydroxytryptamine (5-HT), and for the oxygen radical-mediated oxidation of this alkaloid. The major initial product of the hydroxyl radical (HO.)-mediated oxidation of 1 in the presence of free glutathione (GSH), a constituent of nerve terminals and axons, is 8-S-glutathionyl-1-methyl-1,2,3,4-tetrahydro-beta-carboline-5,6-dione (6). When administered into the brains of mice, 6 is a potent toxin (LD50 = 2.9 microg) and evokes episodes of hyperactivity and tremor. Compound 6 binds at the GABA(B) receptor and evokes elevated release and turnover of several neurotransmitters. Furthermore, the GABA(B) receptor antagonist phaclofen attenuates the behavioral response caused by intracerebral administration of 6. These observations suggest that 6 might be an inverse agonist at the GABA(B) receptor site. Accordingly, it is speculated that ethanol drinking might potentiate formation of 6 that contributes to elevated release of several neurotransmitters including dopamine (DA) and endogenous opioids in regions of the brain innervated by serotonergic axon terminals. Subsequent interactions of DA and opioids with their receptors might be related to the initial development of dependence on ethanol. Redox cycling of 6 (and of several putative secondary metabolites) in the presence of intraneuronal antioxidants and molecular oxygen to produce elevated fluxes of cytotoxic reduced oxygen species might contribute to the degeneration of serotonergic pathways. Low levels of 5-HT in certain brain regions of the rat predisposes these animals to drink or augments drinking. Accordingly, 6, formed as a result of ethanol metabolism in the cytoplasm of certain serotonergic axon terminals, might contribute to the initial development of dependence on ethanol, by mediating DA and opioid release, and long-term preference and addiction to the fluid as a result of the progressive degeneration of these neurons.
Assuntos
Alcoolismo/complicações , Carbolinas/metabolismo , Etanol/metabolismo , Transtornos Relacionados ao Uso de Substâncias/etiologia , Animais , Baclofeno/análogos & derivados , Baclofeno/farmacologia , Comportamento Animal/efeitos dos fármacos , Encefalopatias/induzido quimicamente , Radical Hidroxila , Masculino , Camundongos , Camundongos Endogâmicos ICR , Neurotransmissores/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de GABA-B/efeitos dos fármacosRESUMO
We studied 42 infertile men, who had been surgically treated with modified Palomo method, with intraoperative phlebography of single or multiple testicular veins. We evaluated the efficacy of the performed procedure as well as the presence of other ways of recoil outflow and the connections between the venous vessels of the right testis. In 42 cases surgically treated men with varicocele only in 4 cases the varicocele have been observed additionally on the right side. We are of the opinion that the intraoperative phlebography allows us to performed the proper and the most effective method of the operation of varicocele.
Assuntos
Cuidados Intraoperatórios , Varicocele/diagnóstico , Varicocele/cirurgia , Adulto , Humanos , Masculino , Flebografia/métodos , Testículo/irrigação sanguínea , Testículo/diagnóstico por imagemRESUMO
Authors present methods of treatments at the Clinic of Urology Medical University of Lódz in patients after gynecological tumors with ureteral strictures caused by radiotherapy or progression of cancer.
Assuntos
Neoplasias dos Genitais Femininos/radioterapia , Obstrução Ureteral/etiologia , Obstrução Ureteral/cirurgia , Feminino , Neoplasias dos Genitais Femininos/diagnóstico por imagem , Humanos , Radioterapia/efeitos adversos , Tomografia Computadorizada por Raios XRESUMO
In the light of reports in the literature the data are presented on the importance of glucose-6-phosphate dehydrogenase in cell metabolism. The effect of decreased enzyme activity or its complete absence on the functions of the cell, and the clinical conditions associated with deficient enzyme activity are described. The influence is discussed of the genetic determination of the enzyme on the occurrence of phenotypic effects, and the use of the mosaicism phenomenon in the study on the pathogenesis of certain disturbances. Several reports from the literature are quoted concerning the study of the reverse relationship between a deficiency of the activity of the enzyme and the incidence of carcinoma. The necessity is stressed of including electrophoretic techniques into the studies.
Assuntos
Biomarcadores Tumorais/genética , Glucosefosfato Desidrogenase/genética , Neoplasias/etiologia , Adulto , Idoso , Biomarcadores Tumorais/sangue , Suscetibilidade a Doenças , Ativação Enzimática , Feminino , Marcadores Genéticos/sangue , Glucosefosfato Desidrogenase/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/enzimologia , Neoplasias/genética , FenótipoAssuntos
Nucleosídeos , Pirimidinas , Nucleotídeos de Uracila , Uracila , Brometos , Cloretos , Eletroquímica , Eletrólise , Fluoretos , Concentração de Íons de Hidrogênio , Iodetos , Oxirredução , Polarografia , Polinucleotídeos , Espectrofotometria , UridinaRESUMO
Tryptamine-4,5-dione (T-4,5-D) is formed as a result of oxidation of 5-hydroxytryptamine by superoxide (O(2)(-)(*), nitric oxide (NO*), and peroxynitrite (ONOO(-)). T-4,5-D rapidly inactivates tryptophan hydroxylase (TPH), derived from rat brain, probably as a result of covalent modification of active site cysteine residues. The activity of TPH exposed to T-4,5-D cannot be restored by anaerobic reduction with dithiothreitol (DTT) and ferrous iron (Fe(2+)) indicating that the inactivation is irreversible. 7-S-Glutathionyl-tryptamine-4,5-dione, formed by the rapid reaction between T-4,5-D and glutathione, also inhibits TPH but in this case the activity is restored by anaerobic reduction with DTT/Fe(2+). The results of this investigation may be relevant to the initial reversible and subsequent irreversible inactivation of TPH evoked by methamphetamine and 3,4-methylenedioxymethamphetamine.
Assuntos
Estimulantes do Sistema Nervoso Central/toxicidade , Indolquinonas , Metanfetamina/toxicidade , Triptaminas/farmacologia , Triptofano Hidroxilase/efeitos dos fármacos , Triptofano Hidroxilase/metabolismo , Animais , Encéfalo/enzimologia , Encéfalo/fisiologia , Estimulantes do Sistema Nervoso Central/farmacologia , Cromatografia Líquida de Alta Pressão , Masculino , Metanfetamina/farmacologia , Oxidantes , Oxirredução , Ratos , Ratos Sprague-Dawley , Triptaminas/químicaRESUMO
Both 4,6-dimethyl-2-thipyrimidine and its 1-methyl derivative undergo polarographic reduction in aqueous medium, via a 1e/1H+ reduction to a free radical which rapidly dimerizes to products isolates and identified as 4,4'-bis-(4,6-dimethyl-3,4-dihydropyrimidin-2-thione) and the corresponding 1-methyl dimer. The dimers may be oxidized electrolytically to regenerate the parent monomers. Both dimers also undergo photodissociation to quantitatively regenerate the parent monomers, in high quantum yield, 0.23 and 0.35 M/Einstein. The correlation between electrochemical and photochemical reductions of 2-thiopyrimidines are discussed, as well as the significance of the dimer photodissociation reactions in relation to nucleic acid photochemistry.
Assuntos
Dímeros de Pirimidina , Eletrólise , Concentração de Íons de Hidrogênio , Oxirredução , Fotoquímica , Polarografia , Polietilenoglicóis , Pirimidinas , SulfetosRESUMO
Many new lines of evidence implicate both superoxide anion radical (O2*-) and biogenic amine neurotransmitters in the pathological mechanisms that underlie neuronal damage caused by methamphetamine (MA), glutamate-mediated oxidative toxicity, ischemia-reperfusion, and other neurodegenerative brain disorders. In this investigation the oxidation of 5-hydroxytryptamine (5-HT, serotonin) by an O2*--generating system (xanthine/xanthine oxidase) in buffered aqueous solution at pH 7.4 has been studied. The major product of the O2*--mediated oxidation of 5-HT is tryptamine-4,5-dione (T-4, 5-D). However, O2*- and H2O2, cogenerated by the xanthine oxidase-mediated oxidation of xanthine to uric acid, together react with trace levels of iron that contaminate buffer constituents to give a chemically ill-defined oxo-iron species. This species mediates the oxidation of 5-HT to a C(4)-centered carbocation intermediate that reacts with 5-HT to give 5,5'-dihydroxy-4, 4'-bitryptamine (4,4'-D) and with uric acid to give 9-[3-(2-aminoethyl)-5-hydroxy-1H-indol-4-yl]-2,6,8-triketo-1H,3H, 7H-purine (7) as the major products. These products differ from those formed in the HO*-mediated oxidation of 5-HT under similar conditions. When the reaction is carried out in the presence of the intraneuronal nucleophile glutathione (GSH), T-4,5-D is scavenged to give 7-(S-glutathionyl)tryptamine-4,5-dione, whereas the putative carbocation intermediate is scavenged to give 4-(S-glutathionyl)-5-hydroxytryptamine. T-4,5-D also reacts with the sulfhydryl residues of a model protein, alcohol dehydrogenase, and inhibits its activity. Previous investigators have proposed that T-4, 5-D is a serotonergic neurotoxin. This raises the possibility that T-4,5-D and perhaps other putative intraneuronal metabolites formed by the O2*-/H2O2/oxo-iron-mediated oxidations of 5-HT might be endotoxins that contribute to neurodegeneration in brain regions innervated by serotonergic neurons caused by MA, ischemia-reperfusion, and other neurodegenerative brain disorders.