Avtor/Urednik		Bratanič, Borut
Naslov		Opredelitev sistema bilirubin, albumin in fibroblasti V-79 z elektronsko paramagnetno resonanco
Tip		monografija
Kraj izdaje		Ljubljana
Založnik		Medicinska fakulteta
Leto izdaje		1999
Obseg		str. 100
Jezik		slo
Abstrakt		Introduction. A high unconjugated bilirubin concentration (BR) in serum could present a risk factor for permanent brain damage especially in preterm and sick term new-borns. The toxic effects of BR, because of very low water solubility of this at physiological pH internally H-bonded molecule, depend on its unconjugated, from albumin (ALB) displaced "free BR" fraction. "Free" BR is distributed among numerous compartments (cells and their membranes) and also penetrates through blood brain barrier into central nervous system of new-borns. The exploration of dynamic interactions between BR, ALB and membranes is essential for understanding of BR toxic effects on cells in living organisms. Therefore the research started with EPR (electronic paramagnetic resonance) spectroscopy study of the effects of simultaneous binding of BR and spin labelled palmitic acid on ALB. The toxic effects of BR on the fibroblast cell line (V-79) were studied by the survival and growth rate of cellular cultures. On the cellular membranes of V-79 and mouse neuroblastoma cells (Neuro 2a) the structural and functional changes were determined by EPR spectroscopy. The influence of BR on reduction processes of nitroxide radicals by V-79 cells was studied as a model of BR participation in red-ox processes. Methods. The EPR spectroscopy on Bruker 300 X-band (9 GHz) instrument in 100 mW microwave field, at 100 kH frequency and 0.1 mT amplitude of modulation, with the spin labelling of ALB and cellular membranes was applied. With the binding of BR (Merck, art 24520) and the spin probe (2-(3-carboxypropil)-2-undecil-4,4- dimetiloxazolidin-3-oxyl palmitic acid (HFASL (10,3)) on ALB (bovine albumin, Sigma, No. A-9647) in PBS water solution (pH 7.4; osmolality 290 mmol/kg), conformational changes on ALB molecules were detected by changes in hyperfme splitting of albumin bound spin label spectra. (Abstract truncated at 2000 characters.)
Deskriptorji		BILIRUBIN CELLS, CULTURED FIBROBLASTS NEUROBLASTOMA CELL MEMBRANE PERMEABILITY ELECTRON SPIN RESONANCE SPECTROSCOPY ALBUMINS NITROGEN OXIDES FREE RADICALS