RESUMO
A polysaccharide of Irpex lacteus, a white-rot fungus with lignocellulose-degrading activities, has been used as a commercial medicine for nephritis treatment. Previously, a low-intensity electromagnetic field (LI-EMF) was found to increase the biomass and polysaccharide content of Irpex lacteus and induce twists on the cell surface. In this study, RNA-sequencing (RNA-seq) technology was used to analyze the underlying mechanism of LI-EMF's influence on Irpex lacteus. We identified 3268, 1377, and 941 differentially expressed genes (DEGs) in the LI-EMF-treated samples at recovery times of 0 h, 3 h, and 6 h, respectively, indicating a significant decline in the influence of the LI-EMF treatment on Irpex lacteus with the passage of recovery time. Moreover, 30 upregulated and 14 downregulated DEGs overlapped in the LI-EMF-treated samples at the recovery times of 0 h, 3 h, and 6 h, implying the important lasting effects of LI-EMF. The reliability of the RNA-seq data were validated by quantitative real-time PCR (qRT-PCR). The DEGs related to transcription factors, cell proliferation, cell wall, membrane components, amino acid biosynthesis and metabolism, and polysaccharide biosynthesis and metabolism were significantly enriched in the LI-EMF-treated samples. The experiments confirmed that the LI-EMF treatment significantly increased the content of amino acids with a considerable increase in the content of essential amino acids. Therefore, the global gene expression changes explained the pleiotropic effects of Irpex lacteus induced by the LI-EMF treatment. These findings provide the requisite data for the appropriate design and application of LI-EMF in the fermentation of microorganisms to increase production. Bioelectromagnetics. 40:104-117, 2019. © 2019 Bioelectromagnetics Society.
Assuntos
Basidiomycota/metabolismo , Campos Eletromagnéticos/efeitos adversos , Regulação da Expressão Gênica/efeitos da radiação , Aminoácidos/análise , Aminoácidos/efeitos da radiação , Sequência de Bases , Biomassa , Membrana Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Biblioteca Gênica , Polissacarídeos/efeitos da radiação , Polissacarídeos/toxicidade , Fatores de TempoRESUMO
The caterpillar medicinal mushroom Cordyceps militaris contains many bioactive components, such as adenosine, cordycepin, and polysaccharides. In this study, C. militaris was exposed to 0, 3, 6, or 9 pulses of light irradiation to estimate changes in vitamin D2, bioactive compounds, nonvolatile taste components, and antioxidant properties. In addition, we compared the components and properties of C. militaris mycelia and solid waste medium that had been treated with pulsed light (PL) irradiation. Overall, PL irradiation of C. militaris increased the vitamin D2 content and increased the total amino acid levels 9-48%; the antioxidant properties of the mycelia treated with 0 pulses and of the solid waste medium treated with 3 pulses all exhibited lower half-maximal effective concentrations. Therefore, PL irradiation affected the amounts of bioactive compounds, but the irradiated samples still contained intense umami taste and a sufficient amount of antioxidant components.
Assuntos
Adenosina/metabolismo , Aminoácidos/efeitos da radiação , Antioxidantes/efeitos da radiação , Cordyceps/efeitos da radiação , Ergocalciferóis/efeitos da radiação , Polissacarídeos/efeitos da radiação , Adenosina/efeitos da radiação , Aminoácidos/metabolismo , Antioxidantes/metabolismo , Cordyceps/química , Ergocalciferóis/metabolismo , Carpóforos/química , Carpóforos/efeitos da radiação , Micélio/química , Micélio/efeitos da radiação , Polissacarídeos/metabolismoRESUMO
Ionizing radiation (IR) directly damages cells and tissues or indirectly damages them through reactive free radicals that may lead to longer term adverse sequelae such as cancers, persistent inflammation, or possible death. Potential exposures include nuclear reactor accidents, improper disposal of equipment containing radioactive materials or medical errors, and terrorist attacks. Metabolomics (comprehensive analysis of compounds <1 kDa) by mass spectrometry (MS) has been proposed as a tool for high-throughput biodosimetry and rapid assessment of exposed dose and triage needed. While multiple studies have been dedicated to radiation biomarker discovery, many have utilized liquid chromatography (LC) MS platforms that may not detect particular compounds (e.g., small carboxylic acids or isomers) that complementary analytical tools, such as gas chromatography (GC) time-of-flight (TOF) MS, are ideal for. The current study uses global GC-TOF-MS metabolomics to complement previous LC-MS analyses on nonhuman primate biofluids (urine and serum) 7 days after exposure to 2, 4, 6, 7, and 10 Gy IR. Multivariate data analysis was used to visualize differences between control and IR exposed groups. Univariate analysis was used to determine a combined 26 biomarkers in urine and serum that significantly changed after exposure to IR. We found several metabolites involved in tricarboxylic acid cycle function, amino acid metabolism, and host microbiota that were not previously detected by global and targeted LC-MS studies.
Assuntos
Metabolômica/métodos , Radiação Ionizante , Soro/química , Urina/química , Aminoácidos/metabolismo , Aminoácidos/efeitos da radiação , Animais , Biomarcadores/metabolismo , Ciclo do Ácido Cítrico/efeitos da radiação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microbiota/efeitos da radiação , Primatas , Proteínas/metabolismo , Proteínas/efeitos da radiaçãoRESUMO
Radiotherapy can lead to a reduction of bone density with an increased risk of pathological fractures. Bisphosphonates may represent a preventive treatment option by increasing the density of anorganic bone mineral. Yet it is unknown how bisphosphonates act on irradiated collagen cross-links, which play an essential role for the mechanical stability of bone. The aim of this study was to evaluate the effects of zoledronate on bone collagens and their cross-links after irradiation. The right femur of 37 rats was irradiated with a single dose of 9.5 Gy at a high dose rate using an afterloading machine. Half of the rats (n=18) received additionally a single dose zoledronate (0.1 mg/kg body weight). Fourteen and 100 days after irradiation the femora were collected for histologic evaluation and determination of the collagen cross-links lysylpyridinoline, hydroxylysylpyridinoline, and hydroxyproline. The collagen types were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Fourteen days after treatment the lysylpyridinoline levels of all treatment groups were significantly lower compared to the untreated control. After 100 days, in the combined radiotherapy+zoledronate group significantly lower lysylpyridinoline values were determined (p=0.009). Radiotherapy and/or zoledronate did not change significantly the level of hydroxylysylpyridinoline. The concentration of hydroxyproline was 14 days after irradiation significantly higher in the combined treatment group compared to the control. No significant differences were observed 100 days after treatment. Zoledronate does not have the ability to restore the physiological bone collagen cross-link levels after radiotherapy. However, this would be necessary for regaining the physiological mechanical stability of bone after irradiation and therefore to prevent effectively radiation-induced fractures.
Assuntos
Conservadores da Densidade Óssea/farmacologia , Osso e Ossos/efeitos dos fármacos , Colágeno Tipo I/efeitos dos fármacos , Colágeno Tipo V/efeitos dos fármacos , Difosfonatos/farmacologia , Imidazóis/farmacologia , Aminoácidos/análise , Aminoácidos/efeitos dos fármacos , Aminoácidos/efeitos da radiação , Animais , Osso e Ossos/química , Osso e Ossos/efeitos da radiação , Cromatografia Líquida de Alta Pressão , Colágeno Tipo I/análise , Colágeno Tipo I/efeitos da radiação , Colágeno Tipo V/análise , Colágeno Tipo V/efeitos da radiação , Eletroforese em Gel de Poliacrilamida , Hidroxiprolina/efeitos dos fármacos , Hidroxiprolina/efeitos da radiação , Masculino , Ratos , Ratos Wistar , Ácido ZoledrônicoRESUMO
To assess whether vertebrates can acquire, from their diet, ultraviolet radiation-absorbing mycosporine-like amino acids (MAAs), medaka fish and hairless mice were maintained for 150 and 130 days, respectively, on diets either including Mastocarpus stellatus (rich in MAAs) or the same diets without this red alga. In medaka, the MAAs palythine and asterina-330, present in trace quantities in the diet with added M. stellatus, were present in significantly greater quantities in the eyes of fish fed this diet than in the eyes of control fish. Only traces of MAAs were present in the skin of medaka fed the diet containing MAAs. Shinorine, the principal MAA in M. stellatus, was not found in any tissues of medaka, which raises questions about the specificity of transport of MAAs. In hairless mice, no dietary MAAs were found in the tissues of the eyes, skin, or liver after maintenance on the experimental diet. Low concentrations of shinorine were present only in the tissues of the small and large intestines. These results indicate that MAAs are acquired from their diet and translocated to superficial tissues by teleost fish, but that mammals may be incapable of such. Thus, dietary supplementation with MAAs may be useful in aquacultured species of fish, but MAAs as 'dietary sunscreens' may not be an option for mammals, including humans. Nevertheless, our demonstration of the uptake of shinorine by human skin cancer cells in culture raises evolutionary questions regarding the organ specificity of the capacity for the cellular transport of MAAs.
Assuntos
Aminoácidos/efeitos da radiação , Dieta , Peixes/fisiologia , Camundongos/fisiologia , Raios Ultravioleta , Absorção , Aminoácidos/administração & dosagem , Animais , Eucariotos/química , Feminino , Ácido Chiquímico/administração & dosagem , Ácido Chiquímico/análogos & derivados , Ácido Chiquímico/efeitos da radiação , Protetores Solares/administração & dosagem , Protetores Solares/análiseRESUMO
A new approach to the study of the interaction of amino acid side chains with photoreactive aryl azides was proposed. This approach was based on the drawing together of the reacting groups by the attachment of the reacting compounds to complementary oligonucleotides. Cystamine, histamine, and 1,6-hexamethylenediamine mimicking the cystine, histidine, and lysine residues, respectively, were attached to the 3'-terminal phosphate of the oligonucleotide GGTATCp through a phosphamide bond and used as the targets for photomodification. Derivatives of the oligonucleotide pGATACCAA with the fragment N3C6H4NH- attached directly to its 5'-end by a phosphamide bond or through the spacer -(CH2)nNH- (where n is 2, 4, and 6) were used as photoreagents. Their derivatives containing the same spacer and the N3C6F4CO-NH(CH2)3NH- or 2-N3,5-NO2-C6H3CO-NH(CH2)3NH- residues were also used. The duplexes were photomodified by irradiation with 300-350 nm wavelength light. The maximal yields of the photo-cross-linking were from 22 to 68%. The reagents containing p-azidoaniline residue were found to be the most effective toward the targets. The maximum yields of the photomodification products modeling the side chains of cysteine and lysine were found to vary from 40 to 67% and to depend on the length and the structure of the spacers used. The duplex with the target bearing the imidazole residue (the histidine model) manifested a yield decreased to 25%. This fact was in a good agreement with the data of computer modeling that indicated an unfavorable mutual displacement of the imidazole residue and the photoreactive group.
Assuntos
Aminoácidos/química , Azidas/química , Raios Ultravioleta , Aminoácidos/efeitos da radiação , Azidas/efeitos da radiação , Cistamina/química , Cistamina/efeitos da radiação , Cisteína/química , Cisteína/efeitos da radiação , Diaminas/química , Diaminas/efeitos da radiação , Eletroforese em Gel de Poliacrilamida , Histamina/química , Histamina/efeitos da radiação , Histidina/química , Histidina/efeitos da radiação , Imidazóis/química , Imidazóis/efeitos da radiação , Lisina/química , Lisina/efeitos da radiação , Modelos Moleculares , Oligonucleotídeos/química , Oligonucleotídeos/efeitos da radiaçãoRESUMO
The effect of sodium metabisulfite (MBS) on hydrogen peroxide (HP) production in model and commercial amino acid solutions exposed to phototherapy light was studied. Model and commercial pediatric amino acid solutions were prepared such that the amino acid concentration was 1%. MBS concentration, riboflavin concentration, and duration of exposure to phototherapy light were varied to determine the effect on HP production. Control solutions were kept in the dark. HP production was assayed in the model amino acid solutions by using potassium iodide in the presence of ammonium molybdate. In all experiments, HP production was measured at 360 nm in the presence and absence of catalase. In light-exposed solutions, HP production increased linearly for several hours and reached a plateau by eight hours. A mean maximum of 940 microM was produced (data pooled for all solutions). No detectable HP was generated in the solutions kept in the dark. After two hours of light exposure, it was necessary to add at least 10 times more MBS than is typically found in commercial total parenteral nutrient solutions to scavenge all the HP produced. An average of up to 940 microM of HP was produced in model and commercial pediatric parenteral 1% amino acid solutions in the presence of phototherapy light and clinically relevant concentrations of riboflavin and MBS. Light exposure decreased the antioxidant effect of MBS.
Assuntos
Aminoácidos , Peróxido de Hidrogênio/química , Nutrição Parenteral , Excipientes Farmacêuticos/química , Riboflavina/química , Sulfitos/química , Aminoácidos/efeitos da radiação , Relação Dose-Resposta à Radiação , Estabilidade de Medicamentos , Alimentos Formulados , Técnicas In Vitro , Luz , SoluçõesRESUMO
The aims of the study were to characterize the denaturation of urinary free and conjugated pyridinoline (Pyr) and deoxypyridinoline (Dpyr) on exposure to ultraviolet (UV) and natural light at different pH levels and to study the effects of X- and gamma-irradiation on Pyr and Dpyr in urine and in the mineralized and non-mineralized compartments of human bone. Urine samples from six normal subjects, adjusted to pH 3.0, 7.0 and 9.0 were exposed to UV light for up to 3 days. Urine collections (2 mL and 24 h) from three subjects, pH adjusted to 1.0, 2.0, 3.0, 4.0 and 5.0, were exposed to natural light for up to 1 day. Urine samples and bone slices from seven human cadaveric femurs were irradiated with increasing doses of X-rays (0-100 Gy) and high-dose gamma-radiation (28 kGy). Mineralized and non-mineralized bone were separated using a modification of a published method employing heat denaturation followed by trypsin hydrolysis and analysed for Pyr, Dpyr and hydroxyproline (Hypro). The rate of UV photolysis of urinary Pyr and Dpyr increased with pH and was faster in the free fraction (after 3 days' exposure: free Pyr and Dpyr at pH 7.0 vs. 9.0, P < 0.05, conjugated pH 3.0 vs. 9.0, P < 0.05). Exposure to natural light for 3 h did not significantly decrease urinary Pyr and Dpyr in either sample collections, but levels were reduced in the 2-mL aliquots after exposure for 1 day (P < 0.05). X-irradiation of urine and bone did not affect Pyr and Dpyr. Pyr content was similar in both bone compartments (Pyr/ Hypro = 0.12 +/- 0.004), but Dpyr was higher in the non-mineralized compartment (Dpyr/Hypro = 0.047 +/- 0.002 vs. 0.038 +/- 0.002, P < 0.001). UV light and gamma-irradiation result in denaturation of pyridinium cross-links in urine. These cross-links are present in both the mineralized and non-mineralized bone compartments but are not affected by the doses of gamma-irradiation that denature these cross-links in urine.
Assuntos
Aminoácidos/análise , Fêmur/química , Raios gama , Luz Solar , Raios Ultravioleta , Urina/química , Aminoácidos/efeitos da radiação , Cromatografia Líquida de Alta Pressão , Fêmur/efeitos da radiação , Humanos , Concentração de Íons de Hidrogênio , Fatores de Tempo , Raios XRESUMO
This study was undertaken to determine the effect of low-dose gamma irradiation on aseptically admixed total parenteral nutrition (TPN) solutions to which large inocula of three test bacterial species were added. Microbiological safety levels were quantified in terms of sterility assurance levels (SALs), indicating the probability of contamination occurring expressed as 10-n. The radiation sensitivity (D10 values) of test bacteria in TPN solutions inoculated with a series of bacteria recognized as common contaminants of these products, was determined. Attainable SALs of TPN solutions containing test bacteria were subsequently calculated from the D10 values. Results showed that a minimum absorbed radiation dose as low as 1.5 kGy improved the SAL of aseptically prepared TPN solutions from a probability value of 10(-3) to a value of less than 10(-8) for the microorganisms investigated. At an absorbed dose as high as 8.3 kGy, no measurable changes in amino acid, electrolyte, glucose and lipid components of the solutions were detected. These findings have important implications for the enhancement of microbiological safety levels of aseptically prepared intravenous fluids in general.
Assuntos
Alimentos Fortificados/microbiologia , Nutrição Parenteral Total/normas , Aminoácidos/metabolismo , Aminoácidos/efeitos da radiação , Contagem de Colônia Microbiana , Estabilidade de Medicamentos , Eletrólitos/metabolismo , Eletrólitos/efeitos da radiação , Enterobacter cloacae/efeitos da radiação , Alimentos Fortificados/efeitos da radiação , Raios gama , Glucose/metabolismo , Glucose/efeitos da radiação , Humanos , Concentração de Íons de Hidrogênio , Klebsiella pneumoniae/efeitos da radiação , Metabolismo dos Lipídeos , Lipídeos/efeitos da radiação , Serratia/efeitos da radiação , Soluções , EsterilizaçãoRESUMO
This study examines the influence of low dose X-irradiation on the structure and transport function of cell membranes of rat cerebral cortex. We found that unlike high dose irradiation which promotes membrane damage, low dose irradiation stimulates the SH group of membrane proteins and enhances the ability to control the membrane transport mechanism as reflected by an increase in Na+, K(+)-ATPase activity. The concentration of cysteine (Cys) significantly increased at 25-100 cGy and the concentration of cystine (Cys-Cys) significantly decreased at 25 cGy. It showed no dose dependent changes in tyrosine (Tyr), phenylalanine (Phe) and glycine (Gly). Similarly phospholipid and cholesterol levels were unchanged. Na+, K(+)-ATPase activities significantly decreased at 100 cGy or higher but significantly increased at doses of 25 and 50 cGy.
Assuntos
Aminoácidos/efeitos da radiação , Córtex Cerebral/enzimologia , Córtex Cerebral/efeitos da radiação , ATPase Trocadora de Sódio-Potássio/efeitos da radiação , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Membrana Celular/enzimologia , Membrana Celular/efeitos da radiação , Colesterol/sangue , Colesterol/efeitos da radiação , Relação Dose-Resposta à Radiação , Glicina/sangue , Glicina/química , Glicina/efeitos da radiação , Masculino , Fluidez de Membrana/efeitos da radiação , Proteínas de Membrana/química , Proteínas de Membrana/efeitos da radiação , Dados de Sequência Molecular , Fosfolipídeos/sangue , Fosfolipídeos/efeitos da radiação , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/análiseRESUMO
The effects, on normal human subjects, of 3 minutes exposure to electro-magnetic fields (EMFs) emitted from: A) personal computers, B) color television sets, or C) microwave-ovens, or cellular phones were compared by placing the same large sheet of aluminum foil with a square hole or rectangular band-shaped hole at the chest level (or at the side of the head with the cellular phone), with or without grounding the aluminum foil, using the Bi-Digital O-Ring Test Dysfunction Localization and Molecular Identification Methods with cancer related substances (i.e., Oncogen C-fos Ab2 and mercury in the cell nucleus, Integrin alpha 5 beta 1 in the cell & nuclear membranes, and disappearance of Acetylcholine) as reference control substances. All the above sources of the EMFs not only induced the following various transitional abnormalities on the EMF entry area, but also induced similar abnormalities at the EMF exit area on the back (where the abnormality was found in the same shape as exposed EMF entry area, and the effect lasted for a shorter time than the entry point of the EMF): A) Exposure of the body at about 50 cm from the monitor of some of the typical personal computers resulted in: A1) decrease in Acetylcholine; A2) appearance of circulatory disturbance with the appearance of Thromboxane B2; A3) short-lasting appearance of Oncogen C-fos Ab2; A4) short-lasting appearance of Oncogen C-fos Ab1, though it lasted longer than C-fos Ab2; A5) no appearance of Integrin alpha 5 beta 1. B) part of the chest was exposed at a distance between 1 meter and up to 3 meters from a color television sized anywhere from 13'' to 21'', resulting in: B1) decrease in Acetylcholine; B2) appearance of circulatory disturbance with the appearance of Thromboxane B2; B3) short-lasting appearance of Oncogen C-fos Ab2; B4) short-lasting appearance of Oncogen C-fos Ab1, though it lasted longer than C-fos Ab2; B5) very short-lasting appearance of Integrin alpha 5 beta 1. C) When body was exposed, at a distance of 0.5m-2 meters, to microwaves emitted as leakage from a small microwave oven (about 2.45 GHz with 450 Watt output), the effects usually lasted about 2 to 3 times the exposure time at the exposed area and 1.6 to 2 times the exposure time at the back of the body at the EMF exit area.(ABSTRACT TRUNCATED AT 400 WORDS)
Assuntos
Aminoácidos/análise , Aminoácidos/efeitos da radiação , Química Encefálica/efeitos da radiação , Encéfalo/efeitos da radiação , Campos Eletromagnéticos/efeitos adversos , Análise de Alimentos , Utensílios Domésticos , Integrinas/análise , Integrinas/efeitos da radiação , Micro-Ondas/efeitos adversos , Neoplasias Induzidas por Radiação/etiologia , Proteínas Proto-Oncogênicas c-fos/análise , Proteínas Proto-Oncogênicas c-fos/efeitos da radiação , Radiação , Acetilcolina/análise , Acetilcolina/efeitos da radiação , Adulto , Terminais de Computador , Feminino , Humanos , Masculino , Mercúrio/análise , Mercúrio/efeitos da radiação , Pessoa de Meia-Idade , Receptores de Fibronectina , Telefone , Televisão , Tromboxano B2/análise , Tromboxano B2/efeitos da radiação , Fatores de TempoRESUMO
Pentaphyllous mutants in black gram were isolated in M2 generation of a segregating family, irradiated at 20 kR. The genetic nature of mutants was tested by hybridizing with controls, and chi-square tests applied to the F2 population, proved it to be a monogenic recessive. The pentaphyllous mutant had a greater number of pods and leaves per plant and larger and more root nodules. It also showed improved nutritional value with increased seed protein percentage and no increase in TIA (trypsin inhibitor activity).
Assuntos
Fabaceae/efeitos da radiação , Plantas Medicinais , Aminoácidos/efeitos da radiação , Fabaceae/anatomia & histologia , Fabaceae/efeitos dos fármacos , Fabaceae/genética , Raios gama , Mutação , Proteínas de Vegetais Comestíveis/efeitos da radiaçãoRESUMO
Application of capillary gas chromatography-mass spectrometry (GC-MS) to isolation and identification of radiation-induced DNA base damage including DNA base-amino acid crosslinks is reported. gamma-Irradiated samples of thymine (thy), thymidine (dT), thymidine-5'-monophosphate (pdT), cytosine(cyt),2'-deoxycytidine (dC), 2'-deoxycytidine-5'-monophosphate (pdC), and mixtures of thy, dT and pdT with tyrosine were used as model systems. Trimethylsilylation was used as the derivatization method. Samples containing nucleosides and nucleotides were first subjected to hydrolysis with formic acid or hydrochloric acid to remove sugar or sugar-phosphate moieties, then trimethylsilylated and analyzed by GC-MS. Trimethylsilyl derivatives of radiation-induced monomeric and dimeric products of the model systems mentioned above were shown to have excellent GC properties and easily interpretable mass spectra. The presence of the molecular ion (M+.) and a characteristic (M-CH3)+ ion in the mass spectra facilitated structural elucidation. The complementary use of tert.-butyldimethylsilyl derivatives was also demonstrated. These derivatives provided an intense characteristic (M-57)+ ion in their mass spectra, which may be used to corroborate the molecular weight and to monitor the corresponding compounds in a complex mixture by means of selected-ion monitoring. All gas chromatograms and mass spectra obtained are discussed in detail.
Assuntos
Aminoácidos/efeitos da radiação , DNA/efeitos da radiação , Composição de Bases/efeitos da radiação , Fenômenos Químicos , Química , Cromatografia Gasosa/métodos , Citosina/efeitos da radiação , DNA/análise , Desoxicitidina/efeitos da radiação , Formiatos/efeitos da radiação , Raios gama , Cromatografia Gasosa-Espectrometria de Massas/métodos , Ácido Clorídrico/efeitos da radiação , Hidrólise , Timidina/efeitos da radiação , Timidina Monofosfato/efeitos da radiação , Timina/efeitos da radiação , Tirosina/efeitos da radiaçãoRESUMO
In neonatal nurseries, solutions of amino acids with added vitamins may be exposed to relatively intense light from phototherapy units. Light, especially in the presence of photosensitizers such as certain vitamins, is capable of destroying amino acids. In the present study, the effect of riboflavin on amino acid concentrations in solutions exposed to light was studied. Solutions of crystalline amino acids with and without added riboflavin were infused into shielded collecting vessels for 24 hr under conditions simulating those occurring during phototherapy. Decreases in concentrations of some amino acids were observed with light exposure alone. Decreases in concentrations of methionine, proline, tryptophan, and tyrosine were significantly greater in the presence of riboflavin that in its absence. Riboflavin concentrations were also significantly reduced after light exposure. Although the losses of amino acids are probably not nutritionally significant, the photo-oxidation products are largely unknown and may be toxic.
Assuntos
Aminoácidos/efeitos da radiação , Riboflavina , Concentração de Íons de Hidrogênio , Nitrogênio/análise , Oxirredução , FotoquímicaRESUMO
The effect of UV-irradiation on the growth of pine pollen tubes can be modified by isolated fractions of cell extracts, especially by a fraction containing the cell wall material. Cell extracts irradiated with high UV-doses also stimulate the tube growth of unirradiated pollen grains. RNA, flavonoles and high-energy compounds (ATP, GTP and UTP) did not show any effect concerning tube growth stimulation. Some amino acids modified the tube growth of unirradiated pollen grains, while hydroxyproline, threonine, alanine, glutamic acid, proline and valine stimulated the tube growth. Cysteine, histidine, lysine, tryptophan and glutamine inhibit it. UV irradiation of the basic amino acids (i.e. lysine, arginine and histidine) increased, whereas irradiation of cysteine, glycine, tyrosine and isoleucine additionally decreased the tube growth.
Assuntos
Pólen , Efeitos da Radiação , Árvores , Raios Ultravioleta , Trifosfato de Adenosina/farmacologia , Aminoácidos/efeitos da radiação , Parede Celular , Flavonoides/análogos & derivados , Flavonoides/farmacologia , RNA/farmacologia , Nucleotídeos de Uracila/farmacologiaAssuntos
Aminoácidos/efeitos da radiação , Permeabilidade da Membrana Celular/efeitos da radiação , Eletrólitos/efeitos da radiação , Irradiação de Alimentos , Verduras , Alumínio/efeitos da radiação , Ácido Aspártico/efeitos da radiação , Boro/efeitos da radiação , Cálcio/efeitos da radiação , Cobre/efeitos da radiação , Ferro/efeitos da radiação , Manganês/efeitos da radiação , Fósforo/efeitos da radiação , Radiometria , Sódio/efeitos da radiação , Zinco/efeitos da radiaçãoRESUMO
The preservation of foods by treatment with ionizing radiation can significantly increase the world's food resources by reducing spoilage and waste. However, irradiation can bring about chemical transformations in food and food components resulting in the formation of potential mutagens, particularly hydrogen peroxide and various organic peroxides. In order to evaluate the safety of irradiated foods for general consumption by the public, and, indeed, the safety of all foods subjected to environmental factors such as food additives, pesticides, drugs, air and water pollutants, etc., it is necessary to supplement the usual feeding tests with procedures designed to detect all classes of genetic damage. This article includes a comprehensive critical review of (1) the experimental evidence relating to the presence of mutagenic and cytotoxic agents in irradiated media, as detected by their effects on mammalian and non-mammalian cells; (2) the chemical changes produced in irradiated media, especially those which produce known mutagenic substances; and (3) new and convenient in vivo methods for the detection and evaluation of genetic damage in mammals.