Efeitos da ingestão de semente de linhaça e seu possivel efeito hipocolesterolêmico / Effects of linseed intake and its possible hypocholesterolemic effects

Introdução: O colesterol é essencial para a vida. Em excesso no sangue, deposita-se nas paredes das artérias promovendo seu estreitamento ou obstrução. Objetivos: O objetivo foi verificar o possível efeito hipocolesterolêmico da semente de linhaça. Materiais e Métodos: Utilizaram-se 30 ratos Wistar fêmeas divididos em três grupos: Controle, Hipercolesterolêmico, e Linhaça. Os parâmetros avaliados foram: ingestão hídrica; ingestão de ração; peso corporal; gordura peritoneal e níveis de colesterol; Resultados e Discussão: O grupo controle apresentou maior ingestão hídrica (57,46 ± 0,13mL) e ração (30,68 ± 1,96g) quando comparados ao hipercolesterolêmico e linhaça; Para peso corporal total, somente o controle não sofreu alteração; Em relação ao acúmulo de gordura peritoneal, o grupo hipercolesterolêmico se sobressaiu (17,06 ± 3,99g) em comparação ao linhaça e ao controle; para os níveis de colesterol sérico, o grupo controle obteve (1,14 ± 0,14g), sendo observado portanto no grupo linhaça (1,66 ± 0,16g), uma maior aproximação para o resultado do grupo controle do que do hipercolesterolêmico (2,20 ± 6,32g), resultado que nos leva a reconhecer que a linhaça surtiu efeito benéfico sobre o colesterol. Conclusão: Os resultados obtidos demonstram benefícios na utilização da semente para redução dos níveis de gordura peritoneal, peso total e colesterol

Introduction: Cholesterol is essential for life, when in excess in blood, is deposited on the artery walls promoting its narrowing or obstruction. Objectives: The objective was to verify the possible hypocholesterolemic effect of linseed. Methods: We used 30 female Wistar rats divided into three groups: control, hypercholesterolemic, and linseed. The evaluated parameters were: water intake, feed intake, body weight, peritoneal fat, and cholesterol levels; Results and Discussion: The results were: the control group had a higher fluid intake (57.46 ± 0.13ml) and feed (30.68 ± 1.96g) when compared to hypercholesterolemic and linseed; for total body weight, only the control group did not change; in relation to the accumulation of peritoneal fat, the hypercholesterolemic group stood out (17.06 ± 3.99g) compared to linseed and control; for serum cholesterol levels, the control group obtained (1.14 ± 0.14g), thus being observed in linseed group (1.66 ± 0.16g), closer to the result of the control group than the hypercholesterolemic (2.20 ± 6.32g), a result that leads us to recognize that linseed has had a beneficial effect on cholesterol.Conclusion: The results obtained demonstrate benefits in the use of the seed to reduce levels of peritoneal fat, total weight and cholesterol

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La cinética de la citrulina y la arginina y su valor como factor pronóstico en pacientes pediátricos críticamente enfermos / The value of the kinetics of citrulline and arginine as a prognostic factor in critically ill paediatric patients

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La cinética de la citrulina y la arginina y su valor como factor pronóstico en pacientes pediátricos críticamente enfermos / Citrulline and arginine kinetics and its value as a prognostic factor in pediatric critically ill patients

INTRODUCCIÓN: Se han documentado bajas concentraciones de citrulina y arginina plasmáticas en niños en diversas condiciones patológicas. Hipótesis: La cinética de citrulina y arginina plasmáticas durante la enfermedad crítica pediátrica se correlaciona con parámetros evolutivos clínicos y bioquímicos. PACIENTES Y MÉTODOS: Estudio observacional unicéntrico prospectivo en pacientes de 7 días a 14 años ingresados en Unidad de Cuidados Intensivos Pediátricos (PICU). Los datos bioquímicos y clínicos fueron recogidos al ingreso, a las 12 h, a las 24 h, al 3.er y al 7.° día. RESULTADOS: Un total de 44 pacientes críticamente enfermos fueron incluidos y un grupo control de 51 niños sanos. La citrulina desciende de forma significativa (p < 0,05) a las 12 h de ingreso con niveles bajos mantenidos hasta el día 7, comenzando un aumento progresivo después. La arginina ya está descendida a las 6h, aunque tiene una subida más precoz (día 3). La disminución de citrulina al tercer día se correlaciona directamente con la arginina. Hay correlación entre la elevación de la citrulina al 7.° día con menor duración de ventilación mecánica, menor estancia en PICU y menos complicaciones. Los niveles de citrulina bajos al 7° día aún descendidos el día 7 se asocian con un mayor aumento de PCR y procalcitonina en primeras 24 h. La disminución de arginina en las primeras 12 h se correlaciona inversamente con estancia más larga, mayor número de complicaciones y aumento de reactantes de fase aguda en día 3. CONCLUSIONES: Hay disminución de arginina y citrulina en los primeros días de la enfermedad crítica, con recuperación al 3.er y 7.° día, respectivamente, y existe una relación entre mayor disminución y peor evolución

INTRODUCTION: Low concentrations of plasma citrulline and arginine have been reported in children under various pathological conditions. Hypothesis: Plasma citrulline and arginine levels undergo different kinetics during the early days of critical illness in children according to the severity of symptoms and can be correlated with other clinical and laboratory parameters associated with the SIR. PATIENTS AND METHODS: A single-center prospective observational study in patients 7 days to 14 years admitted to pediatric intensive care unit (PICU). Citrulline and arginine blood levels (blood in dry paper, analysis by mass spectrometry in tandem), acute phase reactants and clinical data were collected on admission, at 12 h, 24 h, 3 and 7 days. RESULTS: A total of 44 critically ill patients were included and control group was formed by 42 healthy children. The citrulline and arginine kinetic analysis showed: 1) Citrulline falls significantly (P<.05) at 12 h of admission; levels remain low until day 7 and begin progressive increase again. 2) Arginine is already lowered at 6h, although an earlier rise occurs (3rd day). 3. The decrease of citrulline in the first 3 days of admission positively correlates with arginine kinetics. Bivariate analysis showed: 1) Correlation of elevated citrulline on the 7th day with shorter duration of mechanical ventilation, lower PICU stay and lower occurrence of complications. The levels of citrulline still descended at day 7 are associated with increased CRP/procalcitonin elevation at first 24 h. 2) The greatest decrease of arginine in the first 12 h is associated with a longer PICU stay and greater number of complications and increase of acute phase reactants at 3 days. CONCLUSIONS: There are decreased levels of arginine and citrulline in the first days at PICU, with recovery at the 3rd and 7th day respectively, and a relationship between a greater decrease and a worse outcome and between a longer income and a higher serum CRP/procalcitonin

Asymmetric dimethyl arginine levels in testicular tissue and blood of rats with induced experimental varicocele / Niveles de dimetilarginina asimétrica en la sangre y el tejido testicular de ratas con varicocele inducido

Introduction. Varicocele is one of the reasons for testicular dysfunction and is frequently known to accompany infertility. The basic pathology of varicocele is the development of endothelial dysfunction. The most important factors in development of endothelial dysfunction are impaired endothelial-linked vasodilatation, increase in free oxygen radicals, reduced synthesis and release of nitric oxide (NO), abnormal vasoconstriction and increased levels of dimethyl arginine. Our aim was to identify and illustrate the relationship between asymmetric dimethyl arginine (ADMA) and NO levels in testicular tissue and plasma of rats with induced experimental varicocele. Materials and methods. Twenty-one adolescent (average 6 weeks) male rats were included in the study and randomly divided into 3 groups. Group 1 (control, n = 6) did not undergo any procedure. Group 2 (sham, n = 6) had the left renal vein circled proximally but ligation was not performed. Group 3 (varicocele-induced, n = 9) had partial ligation of the proximal left renal vein to induce left varicocele. Superoxide dismutase (SOD) enzyme activity and levels of end-products of NO, nitrite and nitrate salts were investigated in testis tissue. Nitrite/nitrate and ADMA levels were investigated in plasma. Histopathological examination was completed with routine hematoxylin-eosine and TUNEL dyes. Results. Tissue SOD and plasma ADMA values were clearly increased in the varicocele group compared to the other groups; tissue and plasma nitrite/nitrate levels were clearly reduced in the varicocele group and this was observed to be statistically significant between the groups. Conclusion. We believe our study has opened an important window on the relationship between infertility observed in varicocele patients and ADMA. We believe that broad-series prospective studies to support this are required (AU)

Introducción. El varicocele es uno de los causantes de la disfunción testicular y comúnmente cursa con infertilidad. La patología de base del varicocele es el desarrollo de la disfunción endotelial. Los factores más importantes para el desarrollo de la disfunción endotelial son la vasodilatación dependiente del endotelio, el aumento de los radicales libres del oxígeno, la reducción en la síntesis y liberación de óxido nítrico (NO), la vasoconstricción anormal y los niveles altos de dimetilarginina. Nuestro objetivo fue identificar e ilustrar la relación existente entre la dimetilarginina asimétrica (ADMA) y los niveles de NO en el tejido testicular y el plasma de ratas con varicocele inducido en laboratorio. Material y métodos. En el estudio se incluyeron veintiuna ratas macho adolescentes (6 semanas de media), que se dividieron en 3 grupos al azar. El Grupo 1 (control, n = 6) no fue sometido a ninguna operación. Al Grupo 2 (grupo quirúrgico de referencia, n = 6) se le rodeó de manera proximal la vena renal izquierda, pero no se realizó la ligadura. En el Grupo 3 (varicocele inducido, n = 9) se realizó una ligadura parcial de la vena renal izquierda para inducir varicocele izquierdo. Se investigaron en el tejido testicular los niveles de actividad de la enzima superóxido dimutasa (SOD) y de productos finales del NO, sales de nitritos y nitratos. Se investigaron los niveles de nitrito/nitrato y de ADMA en el plasma. El análisis histopatológico se completó con tinciones hematoxilina-eosina y TUNEL rutinarias. Resultados. Los valores hísticos de SOD y plasmáticos de ADMA habían sufrido un aumento claro en el grupo de varicocele comparado con los otros grupos; los niveles hísticos y plasmáticos de nitrito/nitrato se habían visto claramente reducidos en el grupo de varicocele, lo cual se entendió como un valor estadístico significativo entre los grupos. Conclusión. Opinamos que nuestra investigación ha abierto una puerta importante a la relación entre la infertilidad en casos de pacientes con varicocele y la ADMA. Para respaldarla, deberían llevarse a cabo amplios estudios prospectivos (AU)

Effect of l-arginine supplementation on insulin resistance and adipocitokines levels in head and neck cancer non diabetic patients after surgery / Efecto de la l-arginina en la resistencia a la insulina y adipocitoquinas en pacientes con tumores de cabeza y cuello sin diabetes tras cirugía

Introduction: Previous studies have found that L-arginine induced beneficial effects over insulin resistance both in type 2 diabetes mellitus patients and healthy individuals. The aim of our study was to investigate whether an L-arginine enteral supplementation (20 g per day) in head and neck cancer patients could modify insulin resistance, leptin and adiponectin levels after surgery. Material and Methods: At surgery 82 patients were randomly allocated to two groups: group I received an enteral diet supplements with a high dose of arginine (20g per day) and group II received an enteral formula without arginine. At basal time and on postoperative day 10, the following parameters were recorded: glucose, c-reactive protein, insulin, HOMA (homeostasis model assessment), leptin and adiponectin. Results: Values of weight, body mass index, fat mass and fat free mass remained unchaged during the acute nutritional intervention in both groups. Insulin levels UI/L (-0.21+/-0.18) and HOMA units (-0.07+/-0.13) decreased in the arginine group. Adiponectin levels (+1.8+/-2.3ng/ml) increased in the arginine group. Conclusion: Short-term enteral L-arginine therapy addeded to usual enteral nutrition of patients affected by head and neck cancer and surgery without diabetes mellitus type 2 is able to improve insulin resistance and adiponectin levels (AU)

Introducción: Algunos trabajos han encontrado que la L-arginina induce efectos beneficiosos sobre la resistencia a la insulina, tanto en pacientes con diabetes tipo 2 como en individuos sanos. El objetivo de nuestro estudio fue investigar si la suplementación enteral de L-arginina (20 g por día) en pacientes con cáncer de cabeza y cuello puede modificar la resistencia a la insulina, los niveles de leptina y adiponectina después de la cirugía. Material y métodos: Tras la cirugía 82 pacientes fueron asignados aleatoriamente a dos grupos: grupo I recibió un enterales suplementos de dieta con una dosis alta de arginina (20 g por día) y el grupo II recibió una fórmula enteral sin arginina. En el momento basal y el día 10 tras la cirugia, se registraron los siguientes parámetros: glucosa, proteína C reactiva, insulina, HOMA (Homeostasis Model Assessment), leptina y adiponectina. Resultados: Los valores de peso, índice de masa corporal, la masa grasa y la masa libre de grasa se mantuvieron sin cambios durante la intervención nutricional aguda en ambos grupos. Los niveles de insulina UI/L (-0,21 + / -0,18) y HOMA (-0,07 + / -0,13) disminuyeron en el grupo de arginina. Los niveles de adiponectina (1,8 + / -2.3ng/ml) aumentaron en el grupo de arginina. Conclusión: La nutrición enteral con L-arginina a corto plazo en los pacientes afectados por cáncer de cabeza y cuello y tras cirugía es capaz de mejorar la resistencia a la insulina y los niveles de adiponectina (AU)

Effect of nitrate and L-arginine therapy on nitric oxide levels in serum, heart, and aorta of fetal hypothyroid rats

Reduced nitric oxide availability and a heterogeneous pattern of nitric oxide synthase activity in some tissues have been reported in hypothyroidism. This study aimed at determining the effects of oral nitrate and L-arginine administration on serum, heart, and aorta nitric oxide metabolite concentrations in fetal hypothyroid rats. In an experimental study, pregnant Wistar rats were administrated tap water or 0.02 % of 6-propyl-2-thiouracil in drinking water during pregnancy and their male pups were followed (n = 8/group). In adult progeny, serum, heart, and aorta nitric oxide metabolite concentrations were measured by the Griess method after 1-week administration of sodium nitrate (500 mg/L) or L-arginine (2 %) in drinking water. Serum thyroid hormone and thyroid-stimulating hormone levels were also measured. Compared to controls, fetal hypothyroid progeny had significantly lower nitric oxide metabolite concentrations in heart (0.32 ± 0.07 vs. 0.90 ± 0.14 nmol/mg protein, p = 0.004) and aorta (2.98±0.56 vs. 6.15±0.74 nmol/mg protein, p = 0.011) tissues. Nitrate therapy restored heart nitric oxide metabolite levels decreased by fetal hypothyroidism, while L-arginine administration further decreased aorta nitric oxide metabolite levels. Sodium nitrate increased and L-arginine decreased serum nitric oxide metabolite levels in both control and fetal hypothyroid animals. In conclusion, nitrate therapy restores decreased heart nitric oxide metabolite levels, whereas L-arginine decreases aorta nitric oxide metabolite levels even further in fetal hypothyroid rats, findings relevant to the cardiovascular consequences of congenital hypothyroidism in adulthood (AU)

The influence of short-term L-arginine supplementation on rats' muscular and hepatic cells in ischemia-reperfusion syndrome

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Due to the complex mechanisms of L-arginine activity, it is difficult to determine the clinical significance of supplementation with this amino acid. The objective of this study was to determine the influence of short-term supplementation with L-arginine in stress conditions, induced by ischemia-reperfusion syndrome, by assessing the damage to muscular and hepatic cells on the basis of creatine kinase (CK), alanine aminotransferase (ALAT) and aspartic aminotransferase (AspAT) activity in blood and the level of oxygen free radicals in analyzed tissues of rats. We observed that induced ischemia of hind limb caused an increase in CK, ALAT and AspAT activity and an increase in the level of free radicals in liver, but not in skeletal muscle. Supplementation withL-arginine led to a reduction in serum activity of CK and AspAT and reduction of the level of free radicals in analysed tissues. Simultaneous supplementation with L-arginine AND L-NAME resulted in a reversal of changes induced by L-arginine supplementation in the case of AspAT and free radicals in skeletal muscle. The results indicate that under conditions of ischemia-reperfusion, short-term administration of L-arginine has a protective effect on skeletal muscle manifesting itself by reduction of CK in the serum and reduction of free radicals level in THIS tissue (AU)

Role of alpha adrenoceptors and nitric oxide on cardiovascular responses in acute and chronic hypertension

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The contribution of á-adrenoceptors and nitric oxide (NO) on the alterations of sympathetically mediated cardiovascular responses after acute (AcH) and chronic (ChH) hypertension was evaluated in pithed aortic coarcted hypertensive rats. Pressor and tachycardia response produced by electrical stimulation of preganglionic sympathetic fibers or exogenous noradrenaline (NA) were recorded in the absence and presence of prazosin (á1-antagonist), rauwolscine (á2-antagonist), or N G-nitro-L-arginine methyl ester (L-NAME; an inhibitor of NO synthase). Compared with age-matched sham-operated rats (Nt), the pressor response produced by electrical stimulation or NA was smaller in AcH rats and larger in ChH rats. Prazosin caused a decrease of pressor response elicited by electrical stimulation or NA in all groups. However, this effect was higher in ChH. Rauwolscine produced a similar increase of sympathetically mediated pressor response in Nt and AcH rats. Nevertheless, this antagonist did not affect the sympathetically mediated pressor response in ChH rats. In addition, rauwolscine did not affect the NA-induced pressor response in all groups. The pressor response elicited by L-NAME was larger in all groups compared without L-NAME and in presence of L-arginine. Moreover, L-NAME in the presence of NA increased sympathetically mediated pressor response is in all groups, compared without it or in the presence of L-arginine. Compared with Nt, basally produced NO in aortic rings was increased in AcH but decreased in ChH. Collectively, our data suggest that decreased cardiovascular reactivity in AcH is due to an increase in basally produced NO. In ChH, enhanced cardiovascular response appears to be associated with a decrease in produced NO and an increase in released NA from sympathetic nerves (AU)

Perinatal L-arginine and antioxidant supplements reduce adult blood pressure but not ameliorate the altered vascular function in spontaneously hypertensive rats

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Spontaneously hypertensive rat (SHR) offspring from L-arginine- and antioxidant-supplemented SHR dams had persistent lower blood pressure in adulthood. We investigated the influence of vascular mechanism in this effect. We analyzed response to acetylcholine and phenylephrine in aorta and superior mesenteric arteries from Wistar–Kyoto (WKY), SHR, and SHR perinatally supplemented with L-arginine and 4-hydroxy-2,2,6,6-tetramethylpiperidinoxyl (TEMPOL; SHR-suppl). Supplements reduced blood pressure persistently in SHR. Relaxation to acetylcholine was greater in WKY than SHR and remained unmodified in SHR-suppl compared with SHR. Acute TEMPOL did not alter relaxation to acetylcholine in WKY but increased it similarly in SHR and SHR-suppl. Phenylephrine contraction was increased in SHR compared to WKY. In SHR-suppl, this response was similar to SHR. Endothelium removal or N-nitro-L-arginine methyl ester (L-NAME) increased contraction to phenylephrine more in WKY than SHR. In SHR-suppl, this was similar to SHR. In both SHR and SHR-suppl, TEMPOL similarly reduced phenylephrine response. This effect was prevented by L-NAME. Results exposed reinforce the concept that oxidative stress during perinatal period is a contributing factor to the development of hypertension in SHR. Results also reveal that the beneficial effect of this supplementation does not appear to be related to improved endothelial function, suggesting that other regulatory mechanisms of blood pressure may be involved (AU)

La suplementación aguda con L-Arginina no previene la hematotoxicidad debida a la quimioterapia neoadyuvanteen pacientes con cáncer de mama / Acute Supplementation of L-Arginine does not prevent the hematotoxicity due to neoadjuvant chemotherapy in patients with breast cancer

Introducción: El cáncer de mama ocupa el primer lugar en morbi-mortalidad por neoplasias en la mujer mexicana. La quimioterapia neoadyuvante es el tratamiento de primera línea para las pacientes con enfermedad localmente avanzada; una de sus principal estoxicidades es la mielosupresión, la cual pueda obligar una demora en el tratamiento o disminución en la dosis. La L-arginina es capaz de prevenir este efecto al mantener un balance de nitrógeno positivo y favorecer la proliferación de células hematopoyéticas Objetivo: Evaluar la eficacia de la suplementación de L-arginina sobre prevención de la toxicidad hemática en pacientes con cáncer de mama con quimioterapia neoadyuvante. Materiales y métodos: Ensayo clínico de asignación aleatoria que administró un suplemento de 30 g de L-arginina en cada ciclo de quimioterapia neoadyuvante. Se determinaron los valores de hemoglobina, hematocrito, leucocitos y linfocitos después de cada aplicación del tratamiento antineoplásico. Se realizaron pruebas ANOVA para evaluar los cambios intragrupales a lo largo del tratamiento y pruebas t-student para muestras independientes para las diferencias intergrupales. Resultados: Se evaluaron 45 pacientes. Todas las pacientes presentaron una disminución significativa en los valores hemáticos en cada ocasión evaluada. No se encontraron diferencias significativas entre grupos. Conclusiones: La suplementación con L-arginina no previene la mielosupresión en pacientes con cáncer de mama localmente avanzado que reciben quimioterapia neoadyuvante. Es necesario realizar más ensayos clínicos que permitan obtener la evidencia para recomendar o no la administración de L-arginina como parte del tratamiento integral del paciente oncológico (AU)

Background: Breast cancer is the first cause of morbid-mortality from neoplasms among Mexican women. Neoadjuvant chemotherapy is the first curse of treatment for patients with locally advances disease; one of its main toxicities is myelo suppression. This can frequently cause the patient to delay her treatment or diminish the dosage. L-arginine can prevent this effect by maintaining a positive nitrogen balance and inducing the proliferation of hematopoietic cells. Objective: To evaluate the efficacy of the supplementation of L-arginine on the prevention of hematologic toxicity in patients with breast cancer undergoing neoadjuvant chemotherapy. response to neoadjuvant chemotherapeutic treatment. Materials and methods: We conducted a randomized clinical trial which administered 30 g of L-argininein each chemotherapy cycle. We determined the values of hemoglobin, hematocrit, leucocytes and lymphocytes after each chemotherapy application. We permormed ANOVA tests in order to evaluate intragrupal changes along the antineoplastic treatment and t-student tests for independent samples for evaluating intergrupal differences. Results: 45 patients were assessed. All of them presented a significant decline in hematologic values eachtime. We did not find significant differences between groups. Conclusions: L-arginine supplementation does not prevent myelosuppression in patients with breast cancer under going neoadjuvant chemotherapy. More clinicaltrials are needs in order to obtain sufficient evidence that allows the recommendation (or not) of L-arginineas part of the integral treatment for the oncology patient (AU)

Efecto de la terapia temprana con L-arginina en el crecimiento intrauterino restringido en la preclampsia. Estudio aleatorizado en mujeres latinoamericanas / Effect of early L-arginine therapy on intrauterine growth restriction in preeclampsia. A randomized controlled trial in Latin-American women

Objetivo: Evaluar el beneficio de la administración temprana de L-arginina en la preeclampsia en el riesgo relativo del crecimiento fetal. Pacientes y métodos: Se aleatorizó a 100 mujeres con preeclampsia a recibir L-arginina o placebo hasta el día del parto. Se comparó a 96 infantes nacidos de gestantes preeclámpticas (50 con tratamiento y 46 sin tratamiento) y con 50 infantes nacidos de gestantes sanas para evaluar el riesgo relativo de crecimiento intrauterino restringido (CIR) y el efecto de L-arginina en éste. El peso al nacer relacionado con la edad gestacional se comparó con curvas de crecimiento respectivas. Los infantes más pequeños del percentil 10 fueron clasificados como CIR. Se utilizaron las pruebas de la U de Mann-Whitney, ANOVA de la χ2 para evaluar las diferencias estadísticas significativas (p < 0,05) entre los grupos. Resultados: No hubo diferencias entre los grupos con preeclampsia antes del estudio. La preeclampsia se asoció en el 21% de los casos al CIR. El riesgo de CIR fue 5 veces más alto en infantes nacidos de preeclámpticas sin terapia de L-arginina comparado con los controles (riesgo relativo [RR] = 5,0; intervalo de confianza [IC], 1,5-16,2) y 2 veces más alto en infantes nacidos de preeclámpticas en tratamiento con L-arginina (RR = 2,0; IC del 95%, 1,9-7,6). Los estudios del perfil biofísico fetal y la puntuación en la prueba de Apgar al nacer demostraron mejoras estadísticamente significativas con el uso de L-arginina en la preeclampsia (p < 0,05). Conclusión: El crecimiento fetal mejora significativamente con la terapia de L-arginina administrada de forma temprana en gestantes con preeclampsia (AU)

Objective: To assess the benefit of early L-arginine administration in preeclampsia on the relative risk to fetal growth. Patients and methods: One-hundred women with preeclampsia were randomized to receive either L-arginine or placebo until the day of delivery. To evaluate the relative risk of intrauterine growth restriction (IUGR) and the effect of L-arginine on this process, 96 live singleton infants of women with preeclampsia (50 with treatment and 46 without treatment) were compared; these infants were also compared with a further 50 control infants of healthy women. Gestational age-related birth weight was compared using standard growth curves. Infants smaller than the 10th percentile were classified as IUGR. The Mann-Witney U-test, ANOVA, and chi-square test were used to evaluate statistically significant differences (P<.05) between the groups. Results: No significant differences were found between the groups with preeclampsia before randomization. Preeclampsia was associated with a 21% reduction in birth weight. The risk of IUGR was five times higher in infants born after preeclampsia without L-arginine therapy than in control pregnancies (RR = 5.0; 95%IC: 1.5-16.2) and was two times higher in infants born after preeclampsia with L-arginine therapy (RR = 2.0; 95% CI: 1.9-7.6). The fetal biophysical profile and Apgar score were significantly more favorable in the L-arginine group (P<.05). Conclusion: Fetal growth markedly improves with early L-arginine therapy in women with preeclampsia (AU)

Arginina, óxido nítrico y función endotelial / Arginine, nitric oxide and endothelial function

La arginina es un aminoácido semiesencial con importantes funciones fisiológicas. Entre ellas destaca su papel como precursora del óxido nítrico, una molécula producida a partir de la arginina por la enzima óxido nítrico sintasa en muchos tejidos y que en el endotelio vascular se comporta como vasodilatadora, antiaterogénica y antiagregante plaquetaria. El estudio detallado de esta reacción enzimática indica que la óxido nítrico sintasa tiene una gran afinidad por su sustrato, la arginina, que se encuentra en concentraciones altas en el endotelio. Por tanto, resultaba sorprendente que el funcionamiento de esta enzima estuviera condicionado por las variaciones en las concentraciones de arginina debidas al aporte nutricional. A esto se le llamó «paradoja de la arginina». Sin embargo, se ha demostrado recientemente la existencia de un inhibidor endógeno de la óxido nítrico sintasa denominado dimetilarginina asimétrica. Este compuesto disminuiría la formación del óxido nítrico por inhibición competitiva con el sustrato natural, la arginina. De ahí la importancia de la suplementación con arginina para contrarrestar este efecto. Además de la arginina, existen otros componentes de la dieta que pueden influir también en la síntesis de óxido nítrico por el endotelio vascular. el endotelio vascular (AU)

Arginine is a semi-essential amino acid with major physiological functions. One of the most outstanding of such is its role as an amino acid precursor of nitric oxide, a molecule produced, in many tissues, from arginine by the nitric oxide synthase enzyme. Within the vascular endothelium, nitric oxide behaves as a vasodilator, antiatherogenic, and anti-plaque aggregation agent. The detailed study of this enzymatic reaction indicates that nitric oxide synthase presents high affinity, aggregation agent. The detailed study of this enzymatic reaction indicates that nitric oxide synthase presents high affinity, for its substrate, arginine, which is found in high concentrations in the endothelium. Consequently, it is surprising that for its substrate, arginine, which is found in high concentrations in the endothelium. Consequently, it is surprising that the functionality of this enzyme is conditioned by variations in concentrations of arginine, produced by nutritional intake. the functionality of this enzyme is conditioned by variations in concentrations of arginine, produced by nutritional intake. This is known as «the arginine paradox». However, the existence of an endogenous nitric oxide synthase inhibitor, This is known as «the arginine paradox». However, the existence of an endogenous nitric oxide synthase inhibitor, known as asymmetric dimethylarginine, has been recently demonstrated. This compound would decrease the formation of nitric oxide through competitive inhibition with the natural substrate, arginine. It is for this reason that dietary supplementation with arginine would be important as a means to counteracting such an effect. In addition to arginine, supplementation with (..) (AU)