| Avtor/Urednik | Živec, Katarina; Ziherl, Kristina | |
| Naslov | Fluidnost eritrocitnih membran pri rakavih bolnikih - študija z elektronsko paramagnetno resonanco | |
| Prevedeni naslov | Fluidity of red blood cells membranes in cancer patients - an electronic paramagnetic resonance study | |
| Tip | članek | |
| Vir | Med Razgl | |
| Vol. in št. | Letnik 45, št. 1 | |
| Leto izdaje | 2006 | |
| Obseg | str. 3-19 | |
| Jezik | slo | |
| Abstrakt | Background: Hypocholesterolemia in cancer patients is a frequent and expected phenomenon. Higher fluidity of plasma membranes (as a result of lower concentration of cholesterol) is a characteristic of most cancer cells. Erythrocytes lack organelles and inner membranes and with that any possibility of endogenous synthesis of lipids. Changes in serum lipid concentration could be shown in the fluidity of erythrocyte cell membranes. Aim: To compare the fluidity of erythrocyte membranes in cancer patients and in healthy controls in relation to serum lipid concentration, type, stage of cancer and age. Hypothesis: Hypocholesterolemia in cancer patients is the cause, that erythrocyte membranes have higher fluidity. Methods: In prospective study we included 49 cancer patients and 25 healthy controls. We studied the membrane fluidity of isolated erythrocytes by the electronic paramagnetic resonance method. In membranes incorporated spin label gives us information (spectrum) about fluidity in the neighborhood. We also added 0.5 M cholesterol to erythrocytes samples from healthy individuals and measured the change in membrane fluidity. Results: Cancer patients in comparison to healthy controls do not have higher erythrocytes membrane fluidity but they do have significantly lower serum lipid concentrations. Fluidity of erythrocyte membranes is higher in patients with higher total serum cholesterol, HDL and LDL. Addition of cholesterol (in vitro) to erythrocytes of healthy individuals significantly increases the concentration of cholesterol in cell membranes and their 17uidity as well. Conclusions: The surprising result that hypocholesterolemia does not cause higher fluidity of erythrocyte membranes we explained with the existence of membrane domains and changes in metabolism in cancer patients. (Abstract truncated at 2000 characters) | |
| Izvleček | Izhodišče: Porabnostna hipoholesterolemija je na račun hitro delečih se rakavih celic pri bolnikih z rakom pogost in pričakovan pojav. Rakave celice imajo povečano fluidnost plazemskih membran zaradi znižane koncentracije holesterola. Eritrociti so celice brez možnosti lastne sinteze lipidov. Spremembe koncentracije serumskih lipidov se lahko kažejo v lipidni sestavi membrane eritrocita in posledično v fluidnosti membrane. Namen: Primerjava fluidnosti membran eritrocitov pri rakavih bolnikih in pri zdravih kontrolah v odvisnosti od koncentracije serumskih lipidov, vrste, stadija raka in starosti. Hipoteza: Membrane eritrocitov rakavih bolnikov imajo zaradi pričakovane hipoholesterolemije povečano fluidnost. Metode: Vključenih je bilo 49 rakavih bolnikov in 25 zdravih kontrol. Fluidnost membran izoliranih eritrocitov smo proučevali z elektronsko paramagnetno resonanco. V membrano smo vgradili spinski označevalec, ki posreduje informacije o fluidnosti membrane v neposredni okolici, kar smo kasneje razbrali iz spektrov. Da bi dodatno dokazali povezavo med vgradnjo holesterola v membrano in fluidnostjo, smo vzorcem eritrocitov zdravih kontrol dodali holesterol in merili posledično spremembo fluidnosti. Rezultati: Bolniki z rakom v primerjavi z zdravimi kontrolami nimajo povečane fluidnosti membran eritrocitov, v serumu pa imajo pomembno manjše vrednosti serumskih lipidov. Fluidnost membran eritrocitov se premosorazmerno povečuje z večanjem vrednosti holesterola v serumu. Dodatek holesterola (0,5 M) eritrocitom v poskusu in vitro pomembno zviša koncentracijo holesterola v eritrocitnih membranah in pa tudi fluidnost teh membran. Zaključek: Presenetljiv rezultat, da hipoholesterolemija ne povzroči večje fluidnosti membran eritrocitov, smo razložili z obstojem membranskih domen in pa spremenjenih metabolnih mehanizmov pri rakavih bolnikih. (Izvleček prekinjen pri 2000 znakih) | |
| Deskriptorji | NEOPLASMS ERYTHROCYTE MEMBRANE MEMBRANE FLUIDITY HYPOLIPOPROTEINEMIA CHOLESTEROL ELECTRON SPIN RESONANCE SPECTROSCOPY |