S. S. Wang, L. Chen, S. K. Xia.
Obsahuje bibliografii a bibliografické odkazy
We studied cadmium toxicity in murine hepatocytes in vitro. Cadmium effects on intracellular free Ca2+ concentration ...(Ca2+i) were assayed, using a laser scanning confocal microscope with a fluorescent probe, Fluo-3/AM. The results showed that administration of cadmium chloride (CdCl2, 5, 10, 25 μM) resulted in a dose-dependent decrease of hepatocyte viability and an elevated aspartate aminotransfe rase (AST) activity in the culture medium (p<0.05 for 25 μM CdCl2 vs. control). Significant increases of lactate dehydrogenase (LDH) activities in 10 and 25 μM CdCl2-exposed groups were observed (p<0.05 and p<0.01, respectively). A greatly decreased albumin content and a more malondialdehyde (MDA) formation also occurred after CdCl2 treatment. The Ca2+ concentrations in the culture medium of CdCl2-exposed hepatocytes were significantly decreased, while Ca2+i appeared to be significantly elevated (p<0.05 or p<0.01 vs. control). We found that in Ca2+-containing hydroxyethyl piperazine ethanesulfonic acid-buffered salt solution (HBSS) only, CdCl2 elicited Ca2+i increases, which comprised an initially slow ascent and a strong elevated phase. However, in Ca2+-containing HBSS with addition of 2-aminoethoxydiphenyl borane (2-APB), CdCl2 caused a mild Ca 2+ i elevation in the absence of an initial rise phase. Removal of extracellular Ca2+ showed that CdCl2 induced an initially slow Ca2+i rise alone without being followed by a markedly elevated phase, but in a Ca2+-free HBSS with addition of 2-APB, CdCl2 failed to elicit the Ca2+i elevation. These results suggest that abnormal Ca2+ homeostasis due to cadmium may be an important mechanism of the development of the toxic effect in murine hepatocytes. Ca2+i elevation in acutely cadmium-exposed hepatocytes is closely related to the extracellular Ca2+ entry and an excessive release of Ca2+ from intracellular stores.
M. B. Patel, M. Majetschak.
Obsahuje bibliografii a bibliografické odkazy
The ubiquitin-proteasome pathway fulfills major biological functions, but its physiologic tissue distribution and the ...interrelationship between pathway component activities and ubiquitin pools are unknown. Therefore, we analyzed free and conjugated ubiquitin, ubiquitin-protein ligation rates (UbPL) and chymotryptic- and tryptic-like proteasome peptidase activities in porcine skeletal muscle, heart, lung, liver, spleen and kidney (n=5 each). There were considerable differences between tissues (p<0.05 for all parameters). Lung and spleen showed high levels of free and conjugated ubiquitin and high UbPL. Proteasome activities were highest in kidney and heart. There were linear relationships between tryptic-like and chymotryptic-like proteasome peptidase activities (r2 = 0.624, p<0.001) and between free and conjugated ubiquitin tissue levels (r2 = 0.623, p<0.001). Tissue levels of free and conjugated ubiquitin correlated linear with UbPL (p<0.005), but they were not correlated with proteasome peptidase activities. The results suggest that tissue ubiquitin pools are tightly regulated and indicate a constant proportion of conjugated ubiquitin. They further support the hypothesis that ubiquitin-protein ligase systems, and probably deubiquitylating enzymes, are key regulators of ubiquitin homeostasis. The detected differences are suggestive of tissue-specific roles of ubiquitin-proteasome pathway components. Besides the known importance of the ubiquitin proteasome pathway in heart, kidney and the immune system, the results suggest the lung as another organ in which ubiquitin proteasome pathway components may also significantly contribute to disease processes.
Amaç: Bu çalışmanın amacı acil servise renal kolik nedeniyle başvuran hastalarda oksidatif stresmarkerlarından olan tiyol/disülfid homeostazı parametreleri ile Nötrofil‐Lenfosit ve ...Platelet‐Lenfositoranlarının (NLO, PLO) beraber kullanımının tanı açısından yararlı olup olmadığını araştırmaktır.Materyal ve Metot: Çalışma 15.05.2018 ile 01.10.2018 tarihleri arasında acil servise başvuran ve çalışmayaalınan 75 hasta ve kontrol grubu olarak belirlenen 47 sağlıklı kişi ile prospektif olarak yapıldı. Erel veNeşelioğlu tarafından yeni geliştirilen bir metot ile oksidatif stres belirteci olan tiyol/disülfid homeostazparametreleri ( Tiyol, disülfid, disülfid / native tiyol, disüfid / total tiyol, native tiyol / total tiyol) ile NLOve PLO hasta ve kontrol grubunda çalışıldı. Üriner taş hastalığı olan ve olmayanlar arasında buparametreler karşılaştırıldı.Bulgular: Renal koliği olanlarda kontrol grubuna göre, NLO, PLO, disülfid, disülfid /native tiyol vedisülfid /total tiyol ortalama değerleri anlamlı derecede yüksek bulunurken (sırasıyla p= 0.010, <0.001,<0.001, <0.001, 0.023, 0.012), native tiyol ve total tiyol ortalama değerleri anlamlı derecede düşükbulundu (sırasıyla p=0.018 ve 0.001). Üriner taş hastalığı olan grupta olmayan gruba göre disülfid,disülfid /native tiyol, NLO ve PLO ortalama değerleri anlamlı derecede yüksek bulundu (sırasıyla p<0.001, <0.001, <0.001, <0.001).Sonuç: NLO ve PLO ile tiyol/disülfid homeostaz parametrelerinin renal kolik tanısında beraberkullanılması bu hastalarda tanının konulması açısından faydalıdır.
PDF