Los sedimentos son considerados reservorios de elementos traza donde, transportados por agua ríos y depositados en la parte baja las cuencas. El trabajo presenta optimización del un método digestión ácida sistema microondas para determinar Fe, Mn Zn a profundidades PK9-1 (0-0,5) m, PK9-2 (0,5-2) m PK9-3 (2-2,7) piezómetro seleccionado al azar total 17 piezómetros. Además, se han utilizado los m...

Chronic administration of benzodiazepine agonists produces behavioral tolerance. For induction of tolerance, the use-dependent down-regulation of gamma-aminobutyric acidA (GABA[A])/ benzodiazepine receptors is a potential cellular mechanism. We previously identified GABA(A) receptors on clathrin-coated vesicles from rat brain, suggesting that surface receptors can be internalized via endocytosi...

Purpose Accumulating evidence indicates that hypothalamic kisspeptin plays a pivotal role in the regulation of the hypothalamic-pituitary-gonadal (HPG) axis. In this study, the direct action of the gamma-aminobutyric acid (GABA)A receptor agonist on kisspeptin-expressing neuronal cells was examined. Methods A hypothalamic cell model of rat hypothalamic cell line R8 (rHypoE8) cells and primary...

Although gamma-aminobutyric acid (GABA)A receptor alpha subunits are important for benzodiazepine (BZD) binding and GABA-current potentiation by BZDs, the presence of a gamma subunit is required for high affinity BZD effects. To determine which regions unique to the gamma2S subunit confer BZD binding and potentiation, we generated chimeric protein combinations of rat gamma2S and alpha1 subunits...

We evaluated whether tolerance to the antagonism of bicuculine-induced seizures by diazepam is associated with changes (i) in the content of mRNAs encoding for gamma-aminobutyric acidA (GABAA) receptor subunits, (ii) in the expression density of these subunits, and (iii) in the 1,4-benzodiazepine binding site characteristics in discrete neocortical structures. We found that in diazepam-tolerant...

This study investigated the role of g-aminobutyric acid (GABA) and GABAA receptors in the spinal cord in the expression of pain behaviors evoked by injection of formalin in concentrations ranging from 0.25 to 2.5% in the hindpaw of the rat. Two approaches were used. The first approach compared the effect of drug treatment to saline at each concentration of formalin. The second approach examined...

Uterine contractions at parturition depend upon a variety of factors, including gamma-aminobutyric acid (GABA)-ergic stimulation. A new subunit of the GABA(A) receptor, pi, has recently been identified as being particularly abundant in the rat uterus. Reduced derivatives of progesterone, such as the 3alpha,5alpha-reduced derivative termed allopregnanolone, modulate GABA(A) receptor activity and...

Many inhaled anesthetics enhance the effect of the inhibitory neurotransmitter gamma aminobutyric acid (GABA), supporting the view that the GABAA receptor could mediate the capacity of inhaled anesthetics to produce immobility in the face of noxious stimulation (i.e., MAC, the minimum alveolar concentration required to suppress movement in response to a noxious stimulus in 50% of subjects). How...

Halothane and propofol enhance the activity of the -aminobutyric acid (GABA) system, which is one of the most important systems in the mechanism of anesthesia. To determine whether halothane and propofol enhance GABAergic responses by the same mechanism, we performed single-channel patch-clamp experiments with rat cortical neurons in primary culture. Each of the open-time and closed-time distri...

This study investigated the role of gamma-aminobutyric acid (GABA) and GABA(A) receptors in the spinal cord in the expression of pain behaviors evoked by injection of formalin in concentrations ranging from 0.25 to 2.5% in the hindpaw of the rat. Two approaches were used. The first approach compared the effect of drug treatment to saline at each concentration of formalin. The second approach ex...