scholarly journals RESISTÊNCIA DE PLANTAS DANINHAS: SELEÇÃO OU INDUÇÃO À MUTAÇÃO PELOS HERBICIDAS INIBIDORES DE ACETOLACTATO

2002 ◽  
Vol 12 ◽  
Author(s):  
RIBAS ANTONIO VIDAL ◽  
LARISSA MACEDO WINKLER
Keyword(s):  
Amino Acids ◽  
Arabidopsis Thaliana ◽  
Amino Acid ◽  
Dna Replication ◽  
Branched Chain Amino Acids ◽  
Amino Acid Synthesis ◽  
Replication Errors ◽  
Resistance To Herbicides ◽  
Branched Chain ◽  
Weed Resistance

A resistência de plantas daninhas aos herbicidas, principalmente os inibidores da síntese de aminoácidos ramificados (isoleucina, leucina e valina), está se propagando no Brasil. A literatura propõem que a resistência aos herbicidas ocorre devido à seleção de indivíduos mutantes já presentes na comunidade vegetal aspergida pelo herbicida. Contudo, durante a replicação do DNA ocorrem erros que são corrigidos por diversas proteínas. Já foi identificada a composição de aminoácidos das proteínas do grupo MutS, responsáveis pela correção de erros replicativos em Arabidopsis thaliana. Com base na elevada composição dos aminoácidos ramificados nas proteínas do grupo MutS, este trabalho questiona se a ausência desses aminoácidos em momentos críticos da replicação do DNA pode estar prejudicando a correção dos erros do DNA das plantas daninhas. Comparações são feitas entre possíveis efeitos de inibidores de acetolactato sintase (ALS) e de enol-piruvil-shiquimatofosfato- sintase (EPSPS). Com base nessas informações sugere-se que herbicidas inibidores da síntese de aminoácidos ramificados podem propiciar o aparecimento de mais indivíduos mutantes resistentes aos mesmos. WEED RESISTANCE: SELECTION OR INDUCTION TO MUTATION BY INHIBITORS OF ACETO LACTATE SYNTASE HERBICIDES Abstract The weed resistance to herbicides is widely spread in Brazil, mainly for the compounds inhibitors of the synthesis of branched-chain amino acids, isoleucine, leucine and valine. The literature proposes that the resistance to herbicides appears as result of selection of mutant individual plants existent in the weed flora prior to herbicide application. However, during DNA replication occur replication errors, that are corrected by several proteins. It is already known the amino acid composition of the proteins from the group MutS, responsible for the correction of replication errors in Arabidopsis thaliana. Based on the high composition of branched-chain amino acids on the group MutS proteins, in this work it is hypothesized that the absence of these amino acids on critical moments of the DNA replication can be interfering on the correction of the DNA replication errors in weeds. Possible effect of aceto lactate syntase (ALS) and enolpyruvil- shiquimato-phosphate syntase (EPSPS) inhibithing herbicides are compared. This review suggests that herbicides inhibitor of branched chain amino acid synthesis can trigger the appearance of more mutant weeds resistant to the herbicides when sprayed by these compounds.

scholarly journals Mechanism of De Novo Branched-Chain Amino Acid Synthesis as an Alternative Electron Sink in Hypoxic Aspergillus nidulans Cells

2010 ◽  
Vol 76 (5) ◽  
pp. 1507-1515 ◽  
Author(s):  
Motoyuki Shimizu ◽  
Tatsuya Fujii ◽  
Shunsuke Masuo ◽  
Naoki Takaya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspergillus Nidulans ◽  
De Novo ◽  
Acid Synthesis ◽  
Branched Chain Amino Acids ◽  
Amino Acid Synthesis ◽  
Lactate Dehydrogenase Activity ◽  
Branched Chain Amino Acid ◽  
Branched Chain

ABSTRACT Although branched-chain amino acids are synthesized as building blocks of proteins, we found that the fungus Aspergillus nidulans excretes them into the culture medium under hypoxia. The transcription of predicted genes for synthesizing branched-chain amino acids was upregulated by hypoxia. A knockout strain of the gene encoding the large subunit of acetohydroxy acid synthase (AHAS), which catalyzes the initial reaction of the synthesis, required branched-chain amino acids for growth and excreted very little of them. Pyruvate, a substrate for AHAS, increased the amount of hypoxic excretion in the wild-type strain. These results indicated that the fungus responds to hypoxia by synthesizing branched-chain amino acids via a de novo mechanism. We also found that the small subunit of AHAS regulated hypoxic branched-chain amino acid production as well as cellular AHAS activity. The AHAS knockout resulted in higher ratios of NADH/NAD+ and NADPH/NADP+ under hypoxia, indicating that the branched-chain amino acid synthesis contributed to NAD+ and NADP+ regeneration. The production of branched-chain amino acids and the hypoxic induction of involved genes were partly repressed in the presence of glucose, where cells produced ethanol and lactate and increased levels of lactate dehydrogenase activity. These indicated that hypoxic branched-chain amino acid synthesis is a unique alternative mechanism that functions in the absence of glucose-to-ethanol/lactate fermentation and oxygen respiration.

Removal of infused amino acids by splanchnic and leg tissues in humans

1986 ◽  
Vol 250 (4) ◽  
pp. E407-E413 ◽  
Author(s):  
R. A. Gelfand ◽  
M. G. Glickman ◽  
R. Jacob ◽  
R. S. Sherwin ◽  
R. A. DeFronzo
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Branched Chain Amino Acids ◽  
Acid Uptake ◽  
Acid Infusion ◽  
Amino Acid Infusion ◽  
Significant Uptake ◽  
Branched Chain

To compare the contributions of splanchnic and skeletal muscle tissues to the disposal of intravenously administered amino acids, regional amino acid exchange was measured across the splanchnic bed and leg in 11 normal volunteers. Postabsorptively, net release of amino acids by leg (largely alanine and glutamine) was complemented by the net splanchnic uptake of amino acids. Amino acid infusion via peripheral vein (0.2 g X kg-1 X h-1) caused a doubling of plasma insulin and glucagon levels and a threefold rise in blood amino acid concentrations. Both splanchnic and leg tissues showed significant uptake of infused amino acids. Splanchnic tissues accounted for approximately 70% of the total body amino acid nitrogen disposal; splanchnic uptake was greatest for the glucogenic amino acids but also included significant quantities of branched-chain amino acids. In contrast, leg amino acid uptake was dominated by the branched-chain amino acids. Based on the measured leg balance, body skeletal muscle was estimated to remove approximately 25-30% of the total infused amino acid load and approximately 65-70% of the infused branched-chain amino acids. Amino acid infusion significantly stimulated both the leg efflux and the splanchnic uptake of glutamine (not contained in the infusate). We conclude that when amino acids are infused peripherally in normal humans, splanchnic viscera (liver and gut) are the major sites of amino acid disposal.

scholarly journals Effects of exercise and pacing loads on myocardial amino acid balance in patients with normal and stenotic coronary arteries, with special reference to branched chain amino acids.

1993 ◽  
Vol 57 (4) ◽  
pp. 272-282 ◽  
Author(s):  
YOSHIHARU YAMADA ◽  
TADASHI ISHIHARA ◽  
MASATAKA FUJIWARA ◽  
SHIGEMI TAMOTO ◽  
ICHIRO SEKI ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Special Reference ◽  
Coronary Arteries ◽  
Branched Chain Amino Acids ◽  
Branched Chain ◽  
Amino Acid Balance

Interorgan metabolism of amino acids in streptozotocin-diabetic ketoacidotic rat

1983 ◽  
Vol 244 (2) ◽  
pp. E151-E158 ◽  
Author(s):  
J. T. Brosnan ◽  
K. C. Man ◽  
D. E. Hall ◽  
S. A. Colbourne ◽  
M. E. Brosnan
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Branched Chain Amino Acids ◽  
Diabetic Rats ◽  
Normal Rat ◽  
Diabetic Brain ◽  
Streptozotocin Diabetic Rats ◽  
Branched Chain ◽  
Amino Acid Concentrations

Amino acid concentrations in whole blood, liver, kidney, skeletal muscle, and brain were measured and arteriovenous differences calculated for head, hindlimb, kidney, gut, and liver in control and streptozotocin-diabetic rats. In the control rats, glutamine was released by muscle and utilized by intestine, intestine released citrulline and alanine, liver removed alanine, and the kidneys removed glycine and produced serine. In diabetic rats, the major changes from the pattern of fluxes seen in the normal rat were the release of many amino acids from muscle, with glutamine and alanine predominating, and the uptake of these amino acids by the liver. Glutamine removal by the intestine was suppressed in diabetes, but a large renal uptake of glutamine was evident. Branched-chain amino acids were removed by the diabetic brain, and consequently, brain levels of a number of large neutral amino acids were decreased in diabetes.

scholarly journals Dietary casein, egg albumin, and branched-chain amino acids attenuate phosphate-induced renal tubulointerstitial injury in rats

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Karin Shimada ◽  
Isao Matsui ◽  
Kazunori Inoue ◽  
Ayumi Matsumoto ◽  
Seiichi Yasuda ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Muscle Weakness ◽  
Branched Chain Amino Acids ◽  
Protective Effects ◽  
Egg Albumin ◽  
Branched Chain Amino Acid ◽  
Renal Tubulointerstitial Fibrosis ◽  
Dietary Casein ◽  
Branched Chain

Abstract Dietary phosphate intake is closely correlated with protein intake. However, the effects of the latter on phosphate-induced organ injuries remain uncertain. Herein, we investigated the effects of low (10.8%), moderate (23.0%), and high (35.2%) dietary casein and egg albumin administration on phosphate-induced organ injuries in rats. The moderate and high casein levels suppressed renal tubulointerstitial fibrosis and maintained mitochondrial integrity in the kidney. The serum creatinine levels were suppressed only in the high casein group. Phosphate-induced muscle weakness was also ameliorated by high dietary casein. The urinary and fecal phosphate levels in the early experiment stage showed that dietary casein did not affect phosphate absorption from the intestine. High dietary egg albumin showed similar kidney protective effects, while the egg albumin effects on muscle weakness were only marginally significant. As the plasma branched-chain amino acid levels were elevated in casein- and egg albumin-fed rats, we analyzed their effects. Dietary supplementation of 10% branched-chain amino acids suppressed phosphate-induced kidney injury and muscle weakness. Although dietary protein restriction is recommended in cases of chronic kidney disease, our findings indicate that the dietary casein, egg albumin, and branched-chain amino acid effects might be reconsidered in the era of a phosphate-enriched diet.

scholarly journals Skin Lesions Associated with Dietary Management of Maple Syrup Urine Disease: a Case Report

2015 ◽  
Vol 7 (4) ◽  
pp. 153-162 ◽  
Author(s):  
Jana Kazandjieva ◽  
Dimitrina Guleva ◽  
Assia Nikolova ◽  
Sonya Márina
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Maple Syrup Urine Disease ◽  
Skin Lesions ◽  
Branched Chain Amino Acids ◽  
Acrodermatitis Enteropathica ◽  
Metabolic Decompensation ◽  
Maple Syrup ◽  
Urine Disease ◽  
Branched Chain

Abstract Leucinosis (maple syrup urine disease - MSUD) is an inherited aminoacidopathy and organic aciduria caused by severe enzyme defect in the metabolic pathway of amino acids: leucine, isoleucine, and valine. The classical variant of the disease is characterized by accumulation of both amino and α-keto acids, particulary the most toxic rapid elevation of circulating leucine and its ketoacid, α-ketoisocaproate, which cause encephalopathy and life-threatening brain swelling. However, patients with the most severe form, classical maple syrup urine disease, may appear normal at birth, but develop acute metabolic decompensation within the first weeks of life with typical symptoms: poor feeding, vomiting, poor weight gain, somnolence and burnt sugar-smelling urine, reminiscent of maple syrup. Early diagnosis and dietary intervention improve the patient’s condition, prevent severe complications, and may allow normal intellectual development. We present a 4-month old infant with leucinosis dignosed 3 months earlier, due to elevated levels of amino acids: leucine, isoleucine and valine. The patient was full-term neonate with an uncomplecated delivery, without any family history of metabolic disorder or consanguinity. The infant was referred to a dermatologist, because of maculopapular exanthema on the scalp, trunk, upper and lower extremities, and exfoliative dermatitis of the perioral, particularly anogenital regions, associated with diarrhea. Skin involvement was associated with poor general condition of the infant exhibiting severe hypotension, anemic syndrome, dyspepsia and neurological symptoms. Exanthema developed a few days after the initiation of nutritional therapy for MSUD: isoleucine-, leucine-, and valine-free powdered medical food (MSUD-2) supplemented with iron. Zink levels were within normal ranges. Rapid skin improvement occurred after adequate branched-chain amino acids supplementation was commenced under regular laboratory control (normal zinc serum level with deficiencies of leucine and valine), skin hygiene with antiseptics, emollients and low potent topical corticosteroids. Treatment of acute metabolic decompensation and dietary restriction of branched-chain amino acids are the main aspects in the management of maple syrup urine disease. Common findings in patients with MSUD include: plasma amino acid imbalance, particularly of essential amino acids, failure to thrive attributed to restriction of particular precursor amino acids and natural proteins, micronutrient deficiencies or higher energy requirement due to chronic illness or inflammation. Due to low intake of branched-chain amino acids, some patients develop skin lesions known as acrodermatitis enteropathica-like syndrome. Here we report a case of an infant who developed acrodermatitis enteropathica-like skin eruptions due to branched-chain amino acid deficiency during treatment of maple syrup urine disease. According to available world literature, this is the first report of acrodermatitis enteropathica-like syndrome in an infant with maple syrup urine disease (leucinosis) in the Republic of Bulgaria.

scholarly journals Amino acid infusion increases the sensitivity of muscle protein synthesis in vivo to insulin. Effect of branched-chain amino acids

1988 ◽  
Vol 254 (2) ◽  
pp. 579-584 ◽  
Author(s):  
P J Garlick ◽  
I Grant
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Branched Chain Amino Acids ◽  
Acid Infusion ◽  
Amino Acid Infusion ◽  
Branched Chain

Rates of muscle protein synthesis were measured in vivo in tissues of post-absorptive young rats that were given intravenous infusions of various combinations of insulin and amino acids. In the absence of amino acid infusion, there was a steady rise in muscle protein synthesis with plasma insulin concentration up to 158 mu units/ml, but when a complete amino acids mixtures was included maximal rates were obtained at 20 mu units/ml. The effect of the complete mixture could be reproduced by a mixture of essential amino acids or of branched-chain amino acids, but not by a non-essential mixture, alanine, methionine or glutamine. It is concluded that amino acids, particularly the branched-chain ones, increase the sensitivity of muscle protein synthesis to insulin.

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