José Antonio Muela Martínez

Sex Differences and In Vitro Effects of Steroids on Serum Aminopeptidase Activities

We studied the possible existence of physiological sex differences in serum aminopeptidase activities in mice, by evaluating the effect of gonadectomy and the in vitro response to the presence in the medium of cholesterol or steroid hormones. Alanyl- and glutamyl-aminopeptidase activities were measured in sera from male, female, orchiectomized and ovariectomized mice, incubated with substrate solutions, and compared with the same groups of serum incubated with substrate solutions including cholesterol, 17-beta-estradiol, testosterone, progesterone or hydrocortisone. Our results demonstrated highly significant sex differences, and an influence of cholesterol and steroid hormones on aminopeptidase activity. Depending on the nature of the aminopeptidase, these enzymes responded in different ways to the presence of these substances and also responded differently to gonadectomy. For alanyl-aminopeptidase activity, but not for glutamyl-aminopeptidase activity, there was a clear difference in response between males and females to incubation of the serum with steroid hormones.

Sex differences and age-related changes in human serum aminopeptidase A activity

Given that aminopeptidase A is primarily responsible for cleaving aspartic acid and converting angiotensin II to angiotensin III, the purpose of the present study was to evaluate the activity of aminopeptidase A by determination of glutamate aminopeptidase activity (GluAP) and aspartate aminopeptidase activity (AspAP) (reported respectively as aminopeptidase A and angiotensinase A activities) in human serum during development and ageing, in an apparently healthy population of 139 male and 148 female subjects. To measure GluAP and AspAP we used glutamyl- and aspartyl-2-naphthylamide as substrates. Significant age-related increases were observed in GluAP activity in males and females and in AspAP activity in females. In males, there were no age-related differences in AspAP activity. A significant correlation was observed between age and GluAP activity in the population analysed as a whole or according to sex. No correlation was demonstrated between age and AspAP activity either in the whole population or according to sex. These results may reflect the evolution of the functional status of susceptible circulating substrates during development and ageing.

Oral administration of losartan influences aminopeptidase activity in the frontal cortex

Although there is a brain renin-angiotensin system, its mechanisms of control are not fully understood. We studied the effect of oral administration of the AT(1) receptor antagonist losartan on brain aminopeptidase (AP) activity, which plays a major role in neuropeptide metabolism. Six AP activities, related and non-related with the angiotensin (Ang) metabolism, were measured in their soluble and membrane-bound forms in the frontal cortex of control animals and rats treated with losartan, chronically administered via the drinking water. The results demonstrate that soluble pGluAP and membrane-bound AspAP and GluAP increased significantly in losartan-treated animals, indicating that the blockade of the AT(1) receptor stimulates the activity of AP involved in the Ang metabolism. Moreover, the blockade of the AT(1) receptor induces changes not only in the brain angiotensin metabolism, but probably also in that of other neuropeptides.

Changes in membrane‐bound leucine aminopeptidase activity during maturation and ageing of brain

Aminopeptidases are believed to be enzymes that regulate the activity of various neuropeptides. However, their physiological role, as well as their mechanisms of regulation, are not well understood. To analyze a part of the regulatory mechanisms that control the activity of these enzymes, the subcellular distribution of membrane‐bound leucyl aminopeptidase activity was studied in rat brain during development and ageing. Except in fetuses, the enzymic activity was greatest in the microsomal fraction in all ages tested. Except in microsomal and myelin fractions, compared with fetuses, leucyl aminopeptidase activity showed a decrease in 1‐week‐old rats and a subsequent increase to adult levels in 1‐month‐old rats. This profile differed in the microsomal fraction, where the activity increased steadily up to 1‐month‐old rats. After this age, the activity decreased progressively in 5‐month and 24‐month‐old rats. These results may reflect changes in the functional status of the susceptible substrates during development and ageing.

Relación entre adherencia objetiva al tratamiento en la diabetes infantil y variables psicológicas de los cuidadores

Justificacion: La diabetes es una elevacion cronica de glucosa en sangre. En ninos, el tratamiento no es administrado por el paciente sino por su cuidador. Asi, las caracteristicas personales que aseguren la adherencia al tratamiento dependen de otra persona. Objetivo Principal: Identificar que caracteristicas personales y ambientales del cuidador favorecen o interfieren la adherencia al tratamiento. Diseno y Metodologia: Participaron 60 cuidadores principales de ninos diabeticos (edad: 1-15 anos). Evaluandose optimismo, autoeficacia, neuroticismo, estrategias de afrontamiento, estilos educativos, apoyo social (del cuidador), asi como adherencia objetiva en los ninos (analisis sanguineo), ademas de variables demograficas y familiares de ambos. Se realizaron correlaciones y diferencias entre grupos utilizando variables de agrupamiento como tener o no adherencia al tratamiento, entre otras. El estudio duro un ano durante el cual los cuidadores asistieron a sesiones psicoeducativas sobre la enfermedad. Resultados Principales y Conclusiones. El perfil del cuidador con mejor adherencia objetiva: alguien con buenos conocimientos sobre la enfermedad, temor ante las consecuencias de no seguir el tratamiento, acostumbrado a afrontar problemas buscando soluciones, con una actitud y motivacion positivas y sin sentirse culpable. En su relacion con los pacientes muestra un alto grado de control y de afecto (cuidador democratico).

Adhesión autoinformada de las embarazadas con diabetes gestacional al tratamiento después de un programa de educación diabetológica: relación con la ansiedad y algunas variables sociodemográficas

Resumen Introduccion La diabetes gestacional (DG) es una alteracion que puede conllevar complicaciones maternofetales. Por otra parte, la mujer no suele estar preparada ante ese diagnostico y, sin embargo, se necesita su actuacion rapida y constante para controlar la DG. Diferentes estudios informan sobre la influencia negativa de la ansiedad en la adhesion al tratamiento en mujeres con DG. El objetivo de este estudio fue comprobar la influencia de la ansiedad sobre otras variables e intentar encontrar las variables con las que interacciona o sobre las que actua, convirtiendolas en facilitadoras u obstaculizadoras de la adhesion al tratamiento (segun la ansiedad sea baja o alta, respectivamente)d Pacientes y metodo Participaron en este estudio 68 mujeres embarazadas diagnosticadas con DG y pertenecientes al Hospital Universitario Ciudad de Jaen. La ansiedad se midio con la Escala de Ansiedad en Gestantes de Alto Riesgo (EDAEGAR) y la adhesion general, a la dieta, al ejercicio y al autocontrol se evaluo con una entrevista (que tambien media variables sociodemograficas como la edad, el nivel de estudios, la situacion laboral, etc.) tras el programa de educacion diabetologica que se esta llevando a cabo en dicho hospitald Resultados y discusion Los resultados indican una alta adhesion tras el programa, con una peor adhesion de las mujeres con mayor ansiedad. La alta ansiedad potencia los efectos negativos de la adhesion, de la falta de apoyo y/o de la mala opinion del companero sobre el tratamiento; tambien tiene efectos negativos ser mayor de 31 anos y tener hijos (obstaculiza el ejercicio pero facilita el autocontrol). Otras variables con efectos indirectos son comentadas en esta investigacion