Publications by authors named "Denise Bertin Rojas"

Neonates have an immature immune system, which increases their vulnerability to infectious agents and inflammatory insults. The administration of the immunostimulatory agent lipopolysaccharide (LPS) has been shown to induce the expression of pro-inflammatory cytokines and cause behavior alterations in rodents at different ages. However, the effects of LPS administration during the neonatal period and its consequences during immune system maturation remain to be elucidated.

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β-Alanine occurs naturally in the human central nervous system and performs different functions. It can act as either a neurotransmitter or a neuromodulator, depletion of taurine levels and competitive antagonist of γ-aminobutyric acid (GABA). The β-amino acid accumulation exerts an important biological function as delay in brain development, oxidative stress and disturbances in energy metabolism, characterized as an inborn error of metabolism classified as β-alaninemia.

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Although many studies show the toxic effects of proline, recently it has been reported some anti-inflammatory effect of this amino acid. Our principal objective was to investigate the effects of proline on the alterations caused by LPS (lipopolysaccharide) administration in the cerebral cortex and cerebellum of young Wistar rats. The animals were divided into four groups: control (0.

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Sarcosine is an N-methyl derivative of the amino acid glycine, and its elevation in tissues and physiological fluids of patients with sarcosinemia could reflect a deficient pool size of activated 1-carbon units. Sarcosinemia is a rare inherited metabolic condition associated with mental retardation. In the present study, we investigated the acute effect of sarcosine and/or creatine plus pyruvate on some parameters of oxidative stress and energy metabolism in cerebral cortex homogenates of 21-day-old Wistar rats.

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In the present study, we developed an acute chemically induced model of sarcosinemia in Wistar rats. Wistar rats of 7, 14 and 21 postpartum days received sarcosine intraperitoneally in doses of 0.5 mmol/Kg of body weight three time a day at intervals of 3 h.

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Tyrosine accumulates in inborn errors of tyrosine catabolism, especially in tyrosinemia type II. In this disease caused by tyrosine aminotransferase deficiency, eyes, skin, and central nervous system disturbances are found. In the present study, we investigated the chronic effect of tyrosine methyl ester (TME) and/or creatine plus pyruvate on some parameters of oxidative stress and enzyme activities of phosphoryltransfer network in cerebral cortex homogenates of 21-day-old Wistar.

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β-Alanine is a β-amino acid derivative of the degradation of pyrimidine uracil and precursor of the oxidative substrate acetyl-coenzyme A (acetyl-CoA). The accumulation of β-alanine occurs in β-alaninemia, an inborn error of metabolism. Patients with β-alaninemia may develop neurological abnormalities whose mechanisms are far from being understood.

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Maple Syrup Urine Disease is an inborn error of metabolism caused by severe deficiency in the activity of branched-chain α-keto acid dehydrogenase complex. Neurological disorder is common in patients with maple syrup urine disease. Although leucine is considered the main toxic metabolite, the mechanisms underlying the neuropathology of brain injury are poorly understood.

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Lead (Pb(2+)) is a heavy metal that has long been used by humans for a wide range of technological purposes, which is the main reason for its current widespread distribution. Pb(2+) is thought to enter erythrocytes through anion exchange and to remain in the cell by binding to thiol groups. Pyruvate kinase (PK) is a thiol-containing enzyme that plays a key role in erythrocyte cellular energy homeostasis.

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Histidinemia is an inborn error of metabolism of amino acids caused by deficiency of histidase activity in liver and skin with consequent accumulation of histidine in plasma and tissues. Histidinemia is an autosomal recessive trait usually considered harmless to patients and their offspring, but some patients and children born from histidinemic mothers have mild neurologic alterations. Considering that histidinemia is one of the most frequently identified metabolic conditions, in the present study we investigated the effect of L-histidine load to female rats during pregnancy and lactation on some parameters of phosphoryltransfer network in cerebral cortex and hippocampus of the offspring.

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Tyrosine levels are abnormally elevated in tissues and physiological fluids of patients with inborn errors of tyrosine catabolism, especially in tyrosinemia type II, which is caused by deficiency of tyrosine aminotransferase and provokes eyes, skin, and central nervous system disturbances. Considering that the mechanisms of brain damage in these disorders are poorly known, in this study, we investigated the in vivo and in vitro effects of tyrosine on some parameters of energy metabolism in cerebral cortex of 14-day-old Wistar rats. We observed that 2 mM tyrosine inhibited in vitro the pyruvate kinase (PK) activity and that this inhibition was prevented by 1 mM reduced glutathione with 30, 60, and 90 min of preincubation.

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Histidinemia is an inherited metabolic disorder biochemically characterized by high concentrations of histidine in biological fluids. Usually affected patients are asymptomatic although some individuals have mental retardation and speech disorders. Considering the high prevalence of histidinemia and the scarce information on the effects of maternal histidinemia on their progeny, we investigated various parameters of oxidative stress in brain cortex and hippocampus of the offspring from female rats that received histidine (0.

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Phenylketonuria is characterized by a variable degree of mental retardation and other neurological features whose mechanisms are not fully understood. In the present study we investigated the effect of intrahippocampal administration of phenylalanine, isolated or associated with pyruvate or creatine, on rat behavior and on oxidative stress. Sixty-day-old male Wistar rats were randomly divided into 6 groups: saline; phenylalanine; pyruvate; creatine; phenylalanine + pyruvate; phenylalanine + creatine.

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It is known that the accumulation of tryptophan and its metabolites is related to brain damage associated with both hypertryptophanemia and neurodegenerative diseases. In this study, we investigated the effect of tryptophan administration on various parameters of behavior in the open-field task and oxidative stress, and the effects of creatine and pyruvate, on the effect of tryptophan. Forty, 60-day-old male Wistar rats, were randomly divided into four groups: saline, tryptophan, pyruvate + creatine, tryptophan + pyruvate + creatine.

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Tyrosine accumulates in inborn errors of tyrosine catabolism, especially in tyrosinemia type II, where tyrosine levels are highly elevated in tissues and physiological fluids of affected patients. Tyrosinemia type II is a disorder of autosomal recessive inheritance characterized by neurological symptoms similar to those observed in patients with creatine deficiency syndromes. Considering that the mechanisms of brain damage in these disorders are poorly known, in the present study our main objective was to investigate the in vivo and in vitro effects of different concentrations and preincubation times of tyrosine on cytosolic and mitochondrial creatine kinase activities of the cerebral cortex from 14-day-old Wistar rats.

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