Effects of L-Arginine and α / 中国医学科学院学报

Kidney is one of the important organs of the body.With both excretory and endocrine functions,it plays a vital role in regulating the normal physiological state.As a precursor of the nitric oxide(NO)synthesis

Óxido nítrico e arginina di-metil assimétrica: possível via de explicação para o trabalho de parto pré-termo / Nitric oxide and asymmetric dimethyl arginine: a novel pathway to explain preterm labor

O trabalho de parto pré-termo (TPPT) assim como as outras causas de prematuridade respondem pela maior parcela da mortalidade e morbidade neonatal no mundo. Várias vias metabólicas já foram estudadas e diversas alterações já foram encontradas em pacientes que desenvolve TPPT. A via metabólica do óxido nítrico (NO) é reconhecida como um dos possíveis mecanismos de desencadeamento fisiopatológico do TPPT. Níveis elevados de dimetil-arginina assimétrica (ADMA), substância endógena inibidora da NO sintetase, estão relacionados com o desencadeamento de TPPT e com maiores taxas de complicações neonatais. O presente estudo aborda as evidências sobre a relação do TPPT e ADMA e as possíveis aplicações clínicas dessa associação.(AU)

Pre-term labor (PTL), as well as the other causes of prematurity, account for the largest portion of neonatal mortality and morbidity in the world. Several metabolic pathways were studied and a significative number of impairments have already been found in patients who develop PTL. The metabolic pathway of nitric oxide (NO) is recognized as one of the possible mechanisms of pathophysiological PTL?s trigger. High levels of asymmetric dimethyl arginine (ADMA), endogenous inhibitory substance of NO synthetase, are related to the triggering of PTL and with higher rates of neonatal complications. The present study addresses the evidence on the relationship of PTL and ADMA and possible clinical applications of this association.(AU)

Inmunonutrición: segunda parte / Immunonutrition: second part

El concepto de inmunonutrición se refiere a la adición de nutrimentos específicos a los regímenes de nutrición enteral o parenteral, en concentraciones mayores a las habitualmente contenidas en las dietas normales, para lograr un efecto farmacológico determinado que mejore la función inmunitaria. Todos los conceptos mencionados indican que el eje intestinoneuroendocrino tiene un papel significativo al influir en la vulnerabilidad del hospedero a infecciones. Entre los inmunonutrimentos se encuentran: arginina, glutamina, ácidos grasos ù-3, prebióticos, zinc, y vitamina A.

The concept of immunonutrition concerns the addition of specific nutrients to the regimes of enteral or parenteral nutrition, at concentrations greater than those usually contained in normal diets to achieve a given pharmacological effect to improve immune function. All the concepts above indicate that gutneuroendocrine axis plays a significant role in influencing host vulnerability to infection. Among inmunonutriments are: arginine, glutamine, ù-3 fatty acids, prebiotics, zinc, and vitamin A.

Asymmetric dimethylarginine (ADMA) and endothelial dysfunction: implications for atherogenesis: [review]

Atherosclerotic coronary heart disease is the leading cause of morbidity and mortality in industrialized countries, and endothelial dysfunction is considered a precursor phenomenon. The nitric oxide produced by the endothelium under the action of endothelial nitric oxide synthase has important antiatherogenic functions. Its reduced bioavailabilty is the beginning of the atherosclerotic process. The addition of two methyl radicals to arginine, through the action of methyltransferase nuclear proteins, produces asymmetric dimethylarginine, which competes with L-arginine and promotes a reduction in nitric oxide formation in the vascular wall. The asymmetric dimethylarginine, which is itself considered a mediator of the vascular effects of the several risk factors for atherosclerosis, can be eliminated by renal excretion or by the enzymatic action of the dimethylarginine dimethylaminohydrolases. Several basic science and clinical research studies suggest that the increase in asymmetric dimethylarginine occurs in the context of chronic renal insufficiency, dyslipidemia, high blood pressure, diabetes mellitus, and hyperhomocysteinemy, as well as with other conditions. Therapeutic measures to combat atherosclerosis may reverse these asymmetric dimethylarginine effects or at least reduce the concentration of this chemical in the blood. Such an effect can be achieved with competitor molecules or by increasing the expression or activity of its degradation enzyme. Studies are in development to establish the true role of asymmetric dimethylarginine as a marker and mediator of atherosclerosis, with possible therapeutic applications. The main aspects of the formation and degradation of asymmetric dimethylarginine and its implication in the atherogenic process will be addressed in this article.

Papel do óxido nítrico na regulação da circulação pulmonar: implicações fisiológicas, fisiopatológicas e terapêuticas / Role of nitric oxide in the control of the pulmonary circulation: physiological, pathophysiological, and therapeutic implications

O nitric oxide (NO, óxido nítrico) é um mediador endógeno vasoativo que contribui para a homeostase vascular pulmonar. O NO é produzido por três isoformas das nitric oxide synthases (NOS, óxido nítrico sintases)-NOS neuronial (nNOS); NOS induzida (iNOS); e NOS endotelial (eNOS)-estando as três presentes no pulmão. Estudos que utilizaram inibidores farmacológicos ou camundongos knockout têm demonstrado que o NO derivado da eNOS desempenha importantes papéis ao modular o tônus vascular pulmonar e atenuar a hipertensão pulmonar. Por outro lado, estudos focados no papel da iNOS têm mostrado que essa isoforma contribui para a fisiopatologia da lesão pulmonar aguda e da síndrome do desconforto respiratório agudo. Esta revisão objetivou delinear o papel desempenhado pelo NO no controle da circulação pulmonar, tanto em condições fisiológicas como fisiopatológicas. Além disso, revisamos as evidências de que a via L-arginina-NO-guanosina monofosfato cíclico seja um importante alvo farmacológico para a terapia de doenças vasculares pulmonares.

Nitric oxide (NO) is an endogenous vasoactive compound that contributes to pulmonary vascular homeostasis and is produced by three nitric oxide synthase (NOS) isoforms-neuronal NOS (nNOS); inducible NOS (iNOS); and endothelial NOS (eNOS)-all three of which are present in the lung. Studies using pharmacological inhibitors or knockout mice have shown that eNOS-derived NO plays an important role in modulating pulmonary vascular tone and attenuating pulmonary hypertension. However, studies focusing on the role of iNOS have shown that this isoform contributes to the pathophysiology of acute lung injury and acute respiratory distress syndrome. This review aimed at outlining the role played by NO in the control of pulmonary circulation, both under physiological and pathophysiological conditions. In addition, we review the evidence that the L-arginine-NO-cyclic guanosine monophosphate pathway is a major pharmacological target in the treatment of pulmonary vascular diseases.

Antinociceptive action of FK506 in mice.

Immunophilins are abundantly present in the brain as compared to the immune system. Immunophilin-binding agents like FK506 are known to inactivate neuronal nitric oxide synthase (nNOS) by inhibiting calcineurin and decrease the production of nitric oxide. Nitric oxide is involved in the mediation of nociception at the spinal level. In the present study, the effect of FK506 on the tail flick response in mice and the possible involvement of NO-L-arginine pathway in this paradigm was evaluated. FK506 (0.5, 1 and 3 mg/kg, ip) produced a significant antinociception in the tail flick test. Nitric oxide synthase (NOS) inhibitor L-NAME significantly and dose dependently (10-40 mg/kg, ip) potentiated the FK506 (0.5 mg/kg)-induced antinociception. On the other hand, NOS substrate L-arginine (100, 200 and 400 mg/kg) inhibited the FK506-induced antinociception in a dose-dependent manner. Concomitant administration of L-NAME (20 and 40 mg/kg) with L-arginine (200 mg/kg) blocked the inhibition exerted by L-arginine on the FK506-induced antinociception. Thus, it was concluded that NO- L-arginine pathway may be involved in the FK506-induced antinociception in tail flick test.

Efecto de L-arginina y poliaminas sobre la movilidad espermática / Effect of L-arginine and polyamines on spermatic motility

En este trabajo se destaca la importancia bioquímica y fisiológica en el sistema reproductor masculino de L-arginina, ya que este aminoácido ha sido utilizado con éxito en el tratamiento de algunos problemas de fertilidad. Este aminoácido está relacionado con el metabolismo de las poliaminas putrecinas, espermidina y espermina, moléculas que tienen importancia fisiológica, ya que se ha sugerido su participación como iniciadoras del proceso de movilidad espermática. Se sugieren algunas aplicaciones prácticas de la L-arginina.

Memorias: inmunomodulacion / Memories: immunomodulation

La arginina tiene efectos inmunoestimulatorios, anabolicos y antitumorales. Sus efectos se deben a sintesis de proteinas, poliaminas, nitrogeno, secrecion hormonal y estimulacion de linfocitos T4