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1.
Parasitology ; 151(2): 185-190, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38186337

RESUMEN

Parasitoid wasps, notably egg parasitoids of the family Eupelmidae (Hymenoptera: Chalcidoidea), a key natural enemy of insect pests, offer a sustainable approach to pest management in agriculture. This study investigated the venom apparatus's developmental dynamics across 4 species of eupelmid egg parasitoids: Anastatus. japonicus, Anastatus fulloi, Mesocomys trabalae and Mesocomys albitarsis. A comprehensive anatomical investigation revealed differences in the dimensions of the venom apparatus across different developmental stages in adult females. We found that the venom apparatus of these 4 studied species consists of a venom gland and a reservoir with an associated Dufour's gland. As the length of post-emergence increases, a significant enlargement in the venom apparatus is evident across all the studied parasitoid species. Notably, M. albitarsis consistently exhibites the shortest venom gland length, whereas that of A. fulloi is the longest among the observed species. At the high day age, the width of venom glands of the 2 Mesocomys species surpasses those of the Anastatus species; for the volume of the venom reservoir, there is a steady increase in all 4 species before the age of 6­7 days, with a decline on 8th day, especially for A. japonicus. This research provided new insights into the developmental trajectories of venom apparatus in eupelmid egg parasitoids and the potential impact of venom potency on their success.


Asunto(s)
Avispas , Femenino , Animales , Agricultura
2.
Biology (Basel) ; 12(5)2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37237513

RESUMEN

Parasitic wasps are abundant and diverse Hymenoptera insects that lay their eggs inside or on the external surface of the host and inject venom into the host to create a more favorable environment for the larvae to survive and regulate the host's immunity, metabolism, and development. But research on the composition of egg parasitoid venom is very limited. In this study, we used a combination of transcriptomic and proteomic approaches to identify the protein fractions of the venom in both eupelmid egg parasitoids, Anastatus japonicus and Mesocomys trabalae. We identified 3422 up-regulated venom gland genes (UVGs) in M. trabalae and 3709 in A. japonicus and analyzed their functions comparatively. By proteome sequencing, we identified 956 potential venom proteins in the venom pouch of M. trabalae, of which 186 were contained in UVGs simultaneously. A total of 766 proteins were detected in the venom of A. japonicus, of which 128 venom proteins were highly expressed in the venom glands. At the same time, the functional analysis of these identified venom proteins was carried out separately. We found the venom proteins in M. trabalae are well known but not in A. japonicus, which may be related to the host range. In conclusion, identifying venom proteins in both egg parasitoid species provides a database for studying the function of egg parasitoid venom and its parasitic mechanism.

3.
Chemosphere ; 307(Pt 1): 135727, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35863411

RESUMEN

There is growing interest in deoxynivalenol (DON) exposure during puberty because experimental evidence shows that DON-exposed to adolescents are more sensitive to DON and have limited detoxification ability. Nevertheless, there have been few surveys of DON exposure for adolescents in China. Furthermore, little is known about the effects of collection times on risk exposure. In the study, we estimated the risk of DON exposure for adolescents in Shanghai and explore the effects of collection time, areas, sex and BMI on intake estimates. A total of 315 adolescents aged 14-16 years, including 161 boys and 154 girls, were recruited. Urine samples were collected for three consecutive days and digested with ß-glucuronidase and then purified using a DON-immunoaffinity column (IAC). Total deoxynivalenol levels were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in combination with a stable isotope dilution assay (SIDA). DON was detected in 945 morning urine samples taken from 315 individuals for three consecutive days. The mean estimated dietary intake of DON did not exceed the tolerable daily intake (TDI) of l µg/kg·bw/day, showing that exposure of adolescents in Shanghai is not of concern. However, 10-20% of probable daily intake (PDI) values exceed the TDI, indicating potential adverse effects. In addition, the DON concentration at the population level did not differ for urine samples collected at different times except for those of overweight adolescents. Therefore, assessment of exposure to DON by monitoring the morning urine of a healthy adolescent, except for overweight people, provides an appropriate estimate of exposure and related risk at the population level, but intake estimates for individuals are uncertain; these could be used to assess exposure of adolescents to DON rapidly and effectively for epidemiological investigations.


Asunto(s)
Micotoxinas , Espectrometría de Masas en Tándem , Adolescente , Biomarcadores/análisis , China , Cromatografía Liquida , Femenino , Contaminación de Alimentos/análisis , Glucuronidasa , Humanos , Masculino , Micotoxinas/análisis , Sobrepeso , Estudios Prospectivos , Espectrometría de Masas en Tándem/métodos , Tricotecenos
4.
Acta Pharmacol Sin ; 43(7): 1865-1874, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34789919

RESUMEN

Furmonertinib (AST2818) is a novel third-generation irreversible EGFR TKI and recently has been approved in China for the treatment of non-small cell lung cancer (NSCLC) with EGFR-sensitizing and T790M resistance mutations. In the current study, we developed a semi-mechanistic population pharmacokinetic model to characterize the nonstationary pharmacokinetics (PK) of the furmonertinib and its active metabolite AST5902 simultaneously. The PK data of furmonertinib and AST5902 were obtained from 38 NSCLC patients and 16 healthy volunteers receiving 20-240 mg furmonertinib in three clinical trials. A nonlinear mixed-effects modeling approach was used to describe the PK data. The absorption process of furmonertinib was described by a transit compartment model. The disposition of both furmonertinib and AST5902 was described by a two-compartment model. An indirect response model accounted for the autoinduction of furmonertinib metabolism mediated by CYP3A4. The model-based simulation suggested that furmonertinib clearance was increased in one cycle of treatment (orally once daily for 21 days) compared to baseline, ranging from 1.1 to 1.8 fold corresponding to the dose range of 20-240 mg. The concentration of furmonertinib was decreased over time whereas that of AST5902 was increased. Interestingly, the concentration of the total active compounds (furmonertinib and AST5902) appeared to be stable. The food intake, serum alkaline phosphatase and body weight were identified as statistically significant covariates. The mechanism of food effect on PK was investigated, where the food intake might increase the bioavailability of furmonertinib via increasing the splanchnic blood flow. Overall, a population PK model was successfully developed to characterize the nonstationary PK of furmonertinib and AST5902 simultaneously. The concentrations of total active compounds were less affected by the autoinduction of furmonertinib metabolism.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Receptores ErbB , Alimentos , Humanos , Modelos Biológicos , Mutación , Inhibidores de Proteínas Quinasas
5.
Chin J Integr Med ; 27(4): 252-258, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33037518

RESUMEN

OBJECTIVE: To evaluate whether the efficacy of Getong Tongluo Capsule (, GTC, consisted of total flavone of Radix Puerariae) on improving patients' quality of life and lowering blood pressure are superior to the extract of Ginkgo biloba (EGB) for patients with convalescent-phase ischemic stroke and primary hypertension. METHODS: This randomized, positive-drug- and placebo-controlled, double-blind trial was conducted from September 2015 to October 2017. Totally 477 eligible patients from 18 hospitals in China were randomly assigned in a 2:1:1 ratio to the following interventions, twice a day for 12 weeks: (1) GTC 250 mg plus EGB-matching placebo 40 mg (237 cases, GTC group), (2) EGB 40 mg plus GTC-matching placebo 250 mg (120 cases, EGB group) or (3) GTC-matching placebo 250 mg plus EGB-matching placebo 40 mg (120 cases, placebo group). Moreover, all patients were orally administered aspirin enteric-coated tablets 100 mg, once a day for 12 weeks. The primary outcome was the Barthel Index (BI). The secondary outcomes included the control rate of blood pressure and National Institutes of Health Stroke Scale (NIHSS) scores. The incidence and severity of adverse events (AEs) were calculated and assessed. RESULTS: The BI relative independence rates, the clinical recovery rates of NIHSS, and the total effective rates of NIHSS in the GTC and EGB groups were significantly higher than the placebo group at 12 weeks after treatment (P<0.05), and no statistical significance was found between the GTC and EGB groups (P>0.05). The control rate of blood pressure in the GTC group was significantly higher than the EGB and placebo groups at 12, 18 and 24 weeks after treatment (P<0.01). There were no statistically significant differences in the incidences of AEs, adverse drug reactions, or serious AEs among the 3 groups (P>0.05). CONCLUSION: GTC exhibited significant efficacy in improving patients' quality of life as well as neurological function and controlling hypertension. (Registration No. ChiCTR1800016667).


Asunto(s)
Isquemia Encefálica , Medicamentos Herbarios Chinos/uso terapéutico , Hipertensión , Accidente Cerebrovascular Isquémico , Isquemia Encefálica/tratamiento farmacológico , Cápsulas , Método Doble Ciego , Humanos , Hipertensión/tratamiento farmacológico , Calidad de Vida , Resultado del Tratamiento
6.
Acta Pharmacol Sin ; 41(10): 1366-1376, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32235864

RESUMEN

Alflutinib (AST2818) is a third-generation epidermal growth factor receptor (EGFR) inhibitor that inhibits both EGFR-sensitive mutations and T790M mutations. Previous study has shown that after multiple dosages, alflutinib exhibits nonlinear pharmacokinetics and displays a time- and dose-dependent increase in the apparent clearance, probably due to its self-induction of cytochrome P450 (CYP) enzyme. In this study, we investigated the CYP isozymes involved in the metabolism of alflutinib and evaluated the enzyme inhibition and induction potential of alflutinib and its metabolites. The data showed that alflutinib in human liver microsomes (HLMs) was metabolized mainly by CYP3A4, which could catalyze the formation of AST5902. Alflutinib did not inhibit CYP isozymes in HLMs but could induce CYP3A4 in human hepatocytes. Rifampin is a known strong CYP3A4 inducer and is recommended by the FDA as a positive control in the CYP3A4 induction assay. We found that the induction potential of alflutinib was comparable to that of rifampin. The Emax of CYP3A4 induction by alflutinib in three lots of human hepatocytes were 9.24-, 11.2-, and 10.4-fold, while the fold-induction of rifampin (10 µM) were 7.22-, 19.4- and 9.46-fold, respectively. The EC50 of alflutinib-induced CYP3A4 mRNA expression was 0.25 µM, which was similar to that of rifampin. In addition, AST5902 exhibited much weak CYP3A4 induction potential compared to alflutinib. Given the plasma exposure of alflutinib and AST5902, both are likely to affect the pharmacokinetics of CYP3A4 substrates. Considering that alflutinib is a CYP3A4 substrate and a potent CYP3A4 inducer, drug-drug interactions are expected during alflutinib treatment.


Asunto(s)
Inductores del Citocromo P-450 CYP3A/farmacología , Citocromo P-450 CYP3A/metabolismo , Inducción Enzimática/efectos de los fármacos , Indoles/farmacología , Piridinas/farmacología , Pirimidinas/farmacología , Inductores del Citocromo P-450 CYP3A/metabolismo , Hepatocitos/efectos de los fármacos , Humanos , Indoles/metabolismo , Microsomas Hepáticos/metabolismo , Piridinas/metabolismo , Pirimidinas/metabolismo , Rifampin/farmacología
7.
J Chromatogr A ; 1572: 9-19, 2018 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-30139620

RESUMEN

In this work, a novel synthetic strategy for separation media which quickly specific recognize anthocyanins was developed by dummy molecular imprinting technology and magnetic separation technology. Rutin, similar to cyanidin-3-O-rutinoside structure, was selected as a virtual template. The appropriate molecular imprinting system was selected by NIP library screening method, 4-vinyl pyridine and acetonitrile as functional monomer and solvent respectively. The molecularly imprinted layer was formed on the surface of the magnetic carrier to prepare dummy magnetic molecularly imprinted polymers. The microstructures of prepared composites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). Adsorption kinetics, isothermal adsorption curves and selective specificity were investigated to further reveal the specific recognition mechanism of the adsorbents on anthocyanins. The dummy molecularly imprinted polymers showed a short kinetic equilibrium time, high selectivity (comparing with quercetin and naringin), and satisfying adsorption capacity for anthocyanins. The binding capacity and the imprinting factor of dummy molecularly imprinted polymers can reach 15.69 mg g-1 and 2.05, respectively. In addition, the purity of cyanidin-3-O-rutinoside in the crude extract from Lonicera caerulea increased to 89% after the adsorption of dummy magnetic molecular imprinted polymers. Many favorable capabilities of the prepared molecularly imprinted polymers also provided the basis for further application for separation and purification of anthocyanins in the future.


Asunto(s)
Antocianinas/química , Antocianinas/aislamiento & purificación , Técnicas de Química Analítica/métodos , Magnetismo , Nanopartículas de Magnetita/química , Adsorción , Flavanonas/química , Microscopía Electrónica de Rastreo , Impresión Molecular , Polímeros/química , Quercetina/química , Rutina/química , Solventes/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
8.
PLoS One ; 9(10): e108409, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25285537

RESUMEN

BACKGROUND: Stenotrophomonas maltophilia is emerging as one of the most frequently found bacteria in chronic pulmonary infection. Biofilm is increasingly recognized as a contributing factor to disease pathogenesis. In the present study, a total of 37 isolates of S. maltophilia obtained from chronic pulmonary infection patients were evaluated to the relationship between biofilm production and the relative genes expression. METHODS: The clonal relatedness of isolates was determined by pulse-field gel electrophoresis. Biofilm formation assays were performed by crystal violet assay, and confirmed by Electron microscopy analysis and CLSM analysis. PCR was employed to learn gene distribution and expression. RESULTS: Twenty-four pulsotypes were designated for 37 S. maltophilia isolates, and these 24 pulsotypes exhibited various levels of biofilm production, 8 strong biofilm-producing S. maltophilia strains with OD492 value above 0.6, 14 middle biofilm-producing strains with OD492 average value of 0.4 and 2 weak biofilm-producing strains with OD492 average value of 0.19. CLSM analysis showed that the isolates from the early stage of chronic infection enable to form more highly structured and multilayered biofim than those in the late stage. The prevalence of spgM, rmlA, and rpfF genes was 83.3%, 87.5%, and 50.0% in 24 S. maltophilia strains, respectively, and the presence of rmlA, spgM or rpfF had a close relationship with biofilm formation but did not significantly affect the mean amount of biofilm. Significant mutations of spgM and rmlA were found in both strong and weak biofilm-producing strains. CONCLUSION: Mutations in spgM and rmlA may be relevant to biofilm formation in the clinical isolates of S. maltophilia.


Asunto(s)
Biopelículas , Genes Bacterianos , Stenotrophomonas maltophilia/genética , Stenotrophomonas maltophilia/fisiología , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Electroforesis en Gel de Campo Pulsado , Genotipo , Microscopía Confocal , Datos de Secuencia Molecular , Mutación/genética , Stenotrophomonas maltophilia/aislamiento & purificación , Stenotrophomonas maltophilia/ultraestructura
9.
FEBS J ; 273(6): 1275-84, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16519691

RESUMEN

Neurodegenerative disorders are associated with oxidative stress. Low density lipoprotein (LDL) exists in the brain and is especially sensitive to oxidative damage. Oxidative modification of LDL has been implicated in the pathogenesis of neurodegenerative diseases. Therefore, protecting LDL from oxidation may be essential in the brain. The antioxidative effects of endomorphin 1 (EM1) and endomorphin 2 (EM2), endogenous opioid peptides in the brain, on LDL oxidation has been investigated in vitro. The peroxidation was initiated by either copper ions or a water-soluble initiator 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH). Oxidation of the LDL lipid moiety was monitored by measuring conjugated dienes, thiobarbituric acid reactive substances, and the relative electrophoretic mobility. Low density lipoprotein oxidative modifications were assessed by evaluating apoB carbonylation and fragmentation. Endomorphins markedly and in a concentration-dependent manner inhibited Cu2+ and AAPH induced the oxidation of LDL, due to the free radical scavenging effects of endomorphins. In all assay systems, EM1 was more potent than EM2 and l-glutathione, a major intracellular water-soluble antioxidant. We propose that endomorphins provide protection against free radical-induced neurodegenerative disorders.


Asunto(s)
Encéfalo/metabolismo , Lipoproteínas LDL/metabolismo , Oligopéptidos/fisiología , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Amidinas/farmacología , Antioxidantes/farmacología , Apolipoproteínas A/metabolismo , Cobre/farmacología , Glutatión/fisiología , Humanos , Peroxidación de Lípido , Oligopéptidos/farmacología , Péptidos Opioides/fisiología , Oxidación-Reducción
10.
Pharmazie ; 60(11): 851-5, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16320949

RESUMEN

Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2, EM1) and endomorphin-2 (Tyr-Pro-Phe-Phe-NH2, EM2), the endogenous selective mu-opioid receptor agonists, can inhibit phenylephrine (PE) induced contraction which is related to the release of nitric oxide from vascular endothelium in aorta rings of rats and rabbits. The reduced (CH2NH) amide bond is a useful peptide bond surrogate in the design of opioid mimetics because it could enhance conformational flexibility and metabolic stability. The present work was designed to investigate the vascular activities of interrelated endomorphin analogues: endomorphin-1[psi] (Tyr[psi(CH2NH)]Pro-Trp-Phe-NH2, EM1[psi]) and endomorphin-2[psi] (Tyr[psi(CH2NH)]Pro-Phe-Phe-NH2, EM2[psi]). The effect of EM1[psi] (1, 2, 3, 4, 5 microM) and EM2[psi] (0.001, 0.01, 0.1, 1, 5 microM) were evaluated on rat thoracic aortic rings pre-contracted with PE (0.1 microM). EM1[psi] and EM2[psi] both caused a concentration-dependent relaxation. The IC50 of EM1[psi] and EM2[psi] was 3.332 microM and 1.226 microM, respectively. The vasorelaxant effect of EMs[psi] is 216.9 and 237.1 fold more potent than EMs. Moreover, the vasorelaxant effect of EMs[psi] was blocked by naloxone (NaCl, 1 microM) and was reduced by N(omega)-nitro-L-arginine (L-NNA, 1 microM) and removal of endothelium. The present study demonstrated that EMs[psi] had more potent vasorelaxant effects and their activities were naloxone-sensitive and endothelium-dependent and partially NO-dependent, similar to the mechanism of parent EMs.


Asunto(s)
Músculo Liso Vascular/efectos de los fármacos , Oligopéptidos/farmacología , Vasodilatadores , Animales , Aorta Torácica/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Técnicas In Vitro , NG-Nitroarginina Metil Éster/farmacología , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Óxido Nítrico Sintasa de Tipo III/antagonistas & inhibidores , Fenilefrina/antagonistas & inhibidores , Fenilefrina/farmacología , Ratas , Ratas Wistar , Vasoconstrictores/antagonistas & inhibidores , Vasoconstrictores/farmacología
11.
Life Sci ; 77(10): 1155-65, 2005 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-15878600

RESUMEN

Endomorphin 1 (EM1) and endomorphin 2 (EM2) are highly potent and selective mu-opioid receptor agonists and have significant antinociceptive action. In the mu-selective pocket of endomorphins (EMs), Pro2 residue is a spacer and directs the Tyr1 and Trp3/Phe3 side chains into the required orientation. The present work was designed to substitute the peptide bond between Tyr1 and Pro2 of EMs with a reduced (CH2NH) bond and study the agonist potency and antinociception of EM1[psi] (Tyr[psi(CH2NH)]Pro-Trp-Phe-NH2) and EM2[psi] (Tyr[psi(CH2NH)]Pro-Phe-Phe-NH2). Both EM1[psi] and EM2[psi] are partial mu opioid receptor agonists showing significant loss of agonist potency in GPI assay. However, EMs[psi] exhibited potent supraspinal antinociceptive action in vivo. In the mice tail-flick test, EMs[psi] (1, 5, 10 nmol/mouse, i.c.v.) produced potent and short-lasting antinociception in a dose-dependent and naloxone (1 mg/kg) reversed manner. At the highest dose of 10 nmol, the effect of EM2[psi] was prolonged and more significant than that of EM2. In the rat model of formalin injection induced inflammatory pain, EMs[psi] (0.1, 1, 10 nmol/rat, i.c.v.), like EMs, exerted transient but not dose-dependent antinociception. These results suggested that in the mu-selective pocket of EMs, the rigid conformation induced by the peptide bond between Tyr1 and Pro2 is essential to regulate their agonist properties at the mu opioid receptors. However, the increased conformational flexibility induced by the reduced (CH2NH) bond made less influence on their antinociception.


Asunto(s)
Analgésicos Opioides/farmacología , Oligopéptidos/farmacología , Receptores Opioides/agonistas , Amidas/química , Analgésicos Opioides/síntesis química , Analgésicos Opioides/química , Animales , Relación Dosis-Respuesta a Droga , Formaldehído , Cobayas , Inflamación/fisiopatología , Inyecciones Intraventriculares , Masculino , Ratones , Oligopéptidos/síntesis química , Oligopéptidos/química , Oxidación-Reducción , Dolor/fisiopatología , Dimensión del Dolor/efectos de los fármacos , Conformación Proteica , Ratas , Ratas Wistar , Tiempo de Reacción/efectos de los fármacos , Relación Estructura-Actividad
12.
Protein Pept Lett ; 12(4): 323-6, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15907175

RESUMEN

[Tic(4)]EM1 and [Tic(4)]EM2, new endomorphins (EMs) analogues, caused relaxation of rat aorta rings precontracted with phenylphrine in a concentration-dependent manner and were 240- to 370-fold more potent than EMs. This effect was inhibited by endothelium removal or by incubation with NO synthase inhibitor L-NNA or opioid receptor antagonist naloxone. The results demonstrate that [Tic(4)]EMs have NO- and endothelium-dependent vasorelaxant effects which are mediated by the opioid receptor.


Asunto(s)
Oligopéptidos/farmacología , Tetrahidroisoquinolinas/química , Vasodilatación/efectos de los fármacos , Animales , Aorta/efectos de los fármacos , Aorta/fisiología , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Óxido Nítrico Sintasa/antagonistas & inhibidores , Nitroarginina/farmacología , Ratas , Ratas Wistar , Receptores Opioides mu/fisiología
13.
Biochim Biophys Acta ; 1639(3): 195-202, 2003 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-14636951

RESUMEN

Oxidative stress has been considered to be a major cause of cellular injuries in a variety of chronic health problems, such as carcinogenesis and neurodegenerative disorders. The brain appears to be more susceptible to oxidative damage than other organs. Therefore, the existence of antioxidants may be essential in brain protective systems. The antioxidative and free radical scavenging effects of endomorphin 1 (EM1) and endomorphin 2 (EM2), endogenous opioid peptides in the brain, have been investigated in vitro. The oxidative damage was initiated by a water-soluble initiator 2,2'-azobis(2-amidinopropane hydrocholoride) (AAPH) and hydrogen peroxide (H2O2). The linoleic acid peroxidation, DNA and protein damage were monitored by formation of hydroperoxides, by plasmid pBR 322 DNA nicking assay and single-cell alkaline electrophoresis, and by SDS-polyacrylamide gel electrophoresis. Endomorphins can inhibit lipid peroxidation, DNA strand breakage, and protein fragmentation induced by free radical. Endomorphins also reacted with galvinoxyl radicals in homogeneous solution, and the pseudo-first-order rate constants were determined spectrophotometrically by following the disappearance of galvinoxyl radicals. In all assay systems, EM1 was more potent than EM2 and GSH, a major intracellular water-soluble antioxidant. We propose that endomorphins are one of the protective systems against free radical-induced damage in the brain.


Asunto(s)
Antioxidantes/farmacología , Encéfalo/fisiología , Oligopéptidos/farmacología , Amidinas/toxicidad , Encéfalo/efectos de los fármacos , Ensayo Cometa , Daño del ADN/efectos de los fármacos , Radicales Libres/química , Humanos , Cinética , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/fisiología , Peroxidación de Lípido/efectos de los fármacos , Micelas , Mutágenos/toxicidad , Oligopéptidos/síntesis química , Oligopéptidos/química
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