Metabolic strategies for the degradation of the neuromodulator agmatine in mammals

Agmatine (1-amino-4-guanidinobutane), a precursor for polyamine biosynthesis, has been identified as an important neuromodulator with anticonvulsant, antineurotoxic and antidepressant actions in the brain. In this context it has emerged as an important mediator of addiction/satiety pathways associated with alcohol misuse. Consequently, the regulation of the activity of key enzymes in agmatine metabolism is an attractive strategy to combat alcoholism and related addiction disorders. Agmatine results from the decarboxylation of L-arginine in a reaction catalyzed by arginine decarboxylase (ADC), and can be converted to either guanidine butyraldehyde by diamine oxidase (DAO) or putrescine and urea by the enzyme agmatinase (AGM) or the more recently identified AGM-like protein (ALP). In rat brain, agmatine, AGM and ALP are predominantly localised in areas associated with roles in appetitive and craving (drug-reinstatement) behaviors. Thus, inhibitors of AGM or ALP are promising agents for the treatment of addictions. In this review, the properties of DAO, AGM and ALP are discussed with a view to their role in the agmatine metabolism in mammals

Religiosidad y resiliencia en estudiantes de psicología de una universidad privada de Lima Este

TesisLa investigación tuvo como objetivo principal determinar si existe relación significativa entre la religiosidad y resiliencia en estudiantes de psicología de una Institución Privada de Lima Este. El estudio de corte transversal y de tipo correlacional contó con la población de 155 estudiantes de psicología de ambos sexos, con edades que oscilaron entre 18 y 30 años. Los instrumentos utilizados fueron la Escala de Religiosidad; y la Escala de Resiliencia (ER). Para la confirmación de las hipótesis se empleó la prueba de coeficiente de correlación de Pearson, la cual determinó una relación moderadamente significativa entre religiosidad y resiliencia, así como de sus respectivas dimensiones. Cabe resaltar que la dimensión de perseverancia tiene un nivel alto de correlación con la religiosidad y sus respectivas dimensiones. En tal sentido se concluye que el nivel de religiosidad contribuye de manera positiva en la formación de competencias para afrontar las adversidades

Religiosidad y resiliencia en estudiantes de psicología de una universidad privada de Lima Este

Objetivo: Determinar la relación existente entre religiosidad y resiliencia en una muestra de 156 estudiantes de psicología de 4 ciclos, en una universidad privada de Lima Este. Material y Métodos: La presente investigaciónes de tipo correlacional. Para evaluar la variable religiosidad se utilizó la Escala de Religiosidad (2014) y para la variable de resiliencia, la escala de resiliencia de Wagnild y Young (1993). Los participantes son estudiantes depsicología de una universidad privada de Lima Este, entre las edades de 18 y 30 años, conformada por una muestra no probabilística de 156 sujetos, de ambos sexos y de distinta religión. Resultados: Los resultados muestran unarelación moderadamente significativa entre las dimensiones de religiosidad y resiliencia. Se determinó que los estudiantes, con mayor nivel de práctica de su religión, presentan mayor nivel de resiliencia. Conclusiones: Estosresultados sostienen las consideraciones teóricas respecto a determinar la religiosidad como factor asociado en la formación de la resiliencia

Plasmatic concentrations of ADMA and homocystein in llama (Lama glama) and regulation of arginase type II: an animal resistent to the development of pulmonary hypertension induced by hypoxia

There are animal species that have adapted to life at high altitude and hypobaric hypoxia conditions in the Andean highlands. One such species is the llama (Lama glama), which seem to have developed efficient protective mechanisms to avoid maladaptation resulting from chronic hypoxia, such as a resistance to the development of hypoxia-induced pulmonary hypertension. On the other hand, it is widely known that different models of hypertension can arise as a result of changes in endothelial function. The respect, one of the common causes of deregulation in endothelial vasodilator function have been associated with down-regulation of the NO synthesis and an increase in plasma levels of asymmetric dimethylarginine (ADMA) and homocysteine. Additionally, it is also known that NO production can be regulated by plasma levels of L-arginine as a result of the competition between nitric oxide synthase (NOS) and arginase. The objective of this study, was to determine the baseline concentrations of ADMA and homocysteine in llama, and to evaluate their effect on the arginase pathway and their involvement in the resistance to the development of altitude-induced pulmonary hypertension. METHOD: Lowland and highland newborn sheep and llama were investigated near sea level and at high altitude. Blood determinations of arterial blood gases, ADMA and homocysteine are made and the effect of these on the arginase activity was evaluated. RESULTS: The basal concentrations of ADMA and homocysteine were determined in llama, and they were found to be significantly lower than those found in other species and in addition, the exposure to hypoxia is unable to increase its concentration. On the other hand, it was observed that the llama exhibited 10 times less arginase II activity as compared to sheep, and the expression was not induced by hypoxia. Finally, ADMA y Hcy, has no effect on the type II arginase pathway. CONCLUSION: Based on our results, we propose that low concentrations of ADMA and homocysteine found in llamas, the low expression of arginase type II, DDAH-2 and CBS, as well as its insensitivity to activation by homocysteine could constitute an adaptation mechanism of these animals to the hypoxia.FONDECYT 11075096 114064

Plasmatic Concentrations of ADMA and Homocystein in Llama (Lama glama) and Regulation of Arginase Type II: An Animal Resistent to the Development of Pulmonary Hypertension Induced by Hypoxia

There are animal species that have adapted to life at high altitude and hypobaric hypoxia conditions in the Andean highlands. One such species is the llama (Lama glama), which seem to have developed efficient protective mechanisms to avoid maladaptation resulting from chronic hypoxia, such as a resistance to the development of hypoxia -induced pulmonary hypertension. On the other hand, it is widely known that different models of hypertension can arise as a result of changes in endothelial function. The respect, one of the common causes of deregulation in endothelial vasodilator function have been associated with down-regulation of the NO synthesis and an increase in plasma levels of asymmetric dimethylarginine (ADMA) and homocysteine. Additionally, it is also known that NO production can be regulated by plasma levels of L-arginine as a result of the competition between nitric oxide synthase (NOS) and arginase. The objective of this study, was to determine the baseline concentrations of ADMA and homocysteine in llama, and to evaluate their effect on the arginase pathway and their involvement in the resistance to the development of altitude-induced pulmonary hypertension. METHOD: Lowland and highland newborn sheep and llama were investigated near sea level and at high altitude. Blood determinations of arterial blood gases, ADMA and homocysteíne are made and the effect of these on the arginase activity was evaluated. RESULTS: The basal concentrations of ADMA and homocysteine were determined in llama, and they were found to be significantly lower than those found in other species and in addition, the exposure to hypoxia is unable to increase its concentration. On the other hand, it was observed that the llama exhibited 10 times less arginase II activity as compared to sheep, and the expression was not induced by hypoxia. Finally, ADMA y Hcy, has no effect on the type II arginase pathway. CONCLUSION: Based on our results, we propose that low concentrations of ADMA and homocysteine found in llamas, the low expression of arginase type II, DDAH-2 and CBS, as well as its insensitivity to activation by homocysteine could constitute an adaptation mechanism of these animals to the hypoxia

Functional analysis of the Mn2+ requirement in the catalysis of ureohydrolases arginase and agmatinase - a historical perspective

Ureohydrolases form a conserved family of enzymes with a strict requirement for divalent metal ions for catalytic activity. They catalyze the hydrolysis of the guanidino group and produce urea. In their active sites six highly conserved amino acid residues form a binding pocket for two catalytically essential metal ions that are needed to activate a water molecule to initiate the hydrolysis of the guanidino group in a nucleophilic attack. Focus in this review is on two members of the ureohydrolase family, the Mn–dependent arginase and agmatinase, which play important roles in functions related to replication and cell survival. We will focus in particular on Mn binding interactions, and on how this metal ion contributes to the reaction catalyzed by these enzymes. We also include the agmatinase-like protein (ALP) because it is functionally closely related to agmatinase, also requires at least one Mn ion for catalytic activity, but may possess an active site that differs significantly from all other known ureohydrolases