Search

The role of the glucocorticoid receptor (GR) in senescence was studied in rats of increasing age. Statistically significant changes in the number of GRs from rat liver were detected, whereas the affinity for the ligand triamcinolone acetonide (TA) did not change with increasing age, and was in the range of 1-2 nM. In all cases the number of receptors was lower in rats treated with hormone in vivo relative to untreated animals. In addition, we have found changes in GR activation, as measured by the binding to DNA cellulose in the mentioned age groups. Furthermore, expression of the glucocorticoid hormone (GH)-inducible gene, tyrosine amino transferase (TAT) also showed age-related alterations. We conclude that receptor function shows oscillatory changes during ageing. In addition, response to GH generally declines towards the older age. This. specific periodicity in functional characteristics of the GR may reconcile conflicting results about the receptor number and properties during the ageing process, and marks particular age at which individual organism shows the highest or the lowest sensitivity to the actions of GH. (C) 1999 Elsevier Science Inc. All rights reserved. null

Protein constituents were extracted from chicken drumstick and chicken white meat, separated according to the molecular mass (Mm), using discontinuous SDS-polyacrylamide electrophoresis (SDS-PAGE) and quantified by scanning densitometry. The obtained profiles were compared with the profiles corresponding to the meat samples which were irradiated at -20. +4, and +20 degrees c. It was observed that the irradiation of chicken while meat led to protein scission which was partially unselective (e.g. the amount of proteins whose Mm GT 20 kDa decreased, while the amount of those whose Mm LT 20 kDa increased), and partially selective (e.g, the appearance of Mm congruent to 16 kDa fragment). In the case of chicken drumstick meat the irradiation caused both protein scission and protein crosslinking (unselective and selective, and appearance of 16 kDa fragment). However, in the case of aerated dehydrated egg white proteins, irradiation led only to unselective protein scission. The obtained results are discussed in view of possible application of discontinuous analytical SDS-PAGE combined with laser scanning densitometry for detection of previously irradiated foodstuff. (C) 1999 Elsevier Science Ltd. All rights reserved. 9th Tihany Symposium on Radiation Chemistry, Aug 29-Sep 03, 1998, Tatabanya, Hungary

The impaired glucocorticoid receptor (GR) signaling has long been considered one of cornerstones in understanding the pathophysiology of depression. Phosphorylation of GR is very important for GR function, therefore we investigated: a) whether GR phosphorylation at serine 211 (pGR-S211) and serine 226 (pGR-S226) is altered in patients with episode of major depressive disorder (MDD); b) if neuroticism and negative affective states may be associated with altered GR phosphoisophorms of healthy adults. Phosphorylation at these sites is generally considered to be indicative of receptor activity. We studied leucocytes of : a) 30 MDD patients and 35 controls, and b) 37 healthy subjects, to assess the levels of nuclear total GR (tGR), pGR-S211 and pGR-S226 using Western blot technique. Our results demonstrated increased phosphorylation of GR at S226 and, to a less extent, at S211 in MDD compared to controls. Also, pGR-S226 positively correlated with neuroticism and self report of stress in healthy. In MDD, the pGRS211/ pGR-S226 ratio was decreased (p We examined whether easily accessible peripheral markers of GR activity and disease status in depression exist. Although we examined leucocytes, we propose that reduced GR transcriptional activity could be one of mechanisms of impaired GR function in the brain, resulting in dysfunction of HPA axis observed as a risk for depression.

Alpha1-antitrypsin (AAT), the main protease inhibitor of human sera, was studied in a group of 88 children suffering from different pulmonary diseases, with the hope that some of the potential victims of chronic obstructive lung diseases can be identified in time.AAT genetic phenotypes were determined using acid agarose gel electrophoresis, followed by crossed antigen-antibody electrophoresis in agarose gel. Identification of the banding patterns revealed 10.2% of AAT variants. 4.54% of the patients were MZ, 3.40% were MS and 89.77% were MM. During this study, 1 FF and 1 MV subject were also found. All AAT variants were in the group of younger children, under 6 years of age.

The aim of the present study was to define the stress-induced pattern of cytosolic glucocorticoid receptor (GR) and Hsp70 protein in the liver of male Wistar rats exposed to different stress models: acute (2 h/day) immobilization or cold (4 °C); chronic (21 days) isolation, crowding, swimming or isolation plus swimming and combined (chronic plus acute stress). Changes in plasma levels of corticosterone were studied by radioimmunoassay (RIA). The results obtained by Western immunoblotting showed that both acute stressors led to a significant decrease in cytosolic GR and Hsp70 levels. Compared to acute stress effects, only a weak decrease in the levels of GR and Hsp70 was demonstrated in chronic stress models. Chronically stressed rats, which were subsequently exposed to novel acute stressors (immobilization or cold), showed a lower extent of GR down-regulation when compared to acute stress. The exception was swimming, which partially restores this downregulation. The observed changes in the levels of these major stress-related cellular proteins in liver cytosol lead to the conclusion that chronic stressors compromise intracellular GR down-regulation in the liver.