Erythrocyte membranes in biliary obstruction: Phospholipase A2-induced alterations in lipid composition and morphology
| Autor: | Masaru Takahashi, Yukio Okano, Takashi Sekiya, Isao Hasegawa, Hisaya Iida, Yoshinori Nozawa |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Erythrocytes
food.ingredient Membrane Fluidity Biology Biochemistry Filipin Lecithin Phospholipases A Membrane Lipids chemistry.chemical_compound Hydrolysis food Phospholipase A2 Cholestasis medicine Humans chemistry.chemical_classification Erythrocyte Membrane Fatty Acids Cholestasis Extrahepatic medicine.disease Hemolysis Phospholipases A2 Membrane Enzyme chemistry Phospholipases biology.protein lipids (amino acids peptides and proteins) |
| Zdroj: | Biochemical Medicine. 26:314-325 |
| ISSN: | 0006-2944 |
| DOI: | 10.1016/0006-2944(81)90007-7 |
| Popis: | Without significant hemolysis, phospholipase A2 (N. naja) hydrolyzed lecithin of the outer monolayer of erythrocytes from control subjects and patients with biliary obstruction. The hydrolytic treatment with this enzyme induced more prominent alterations in the morphology of red blood cells in cholestasis—crenation of red blood cells—compared to control cells. Phospholipase A2 hydrolyzed 20 and 40% of erythrocyte membrane lecithin from control subjects and patients with biliary obstruction, respectively. The hydrolysis of lecithin by this enzyme revealed that 85 to 90% of released free fatty acids were unsaturated ones whereas the lysolecithin acyl chain formed was found to be composed mostly of saturated fatty acids (85%). Freeze-fracture electron microscopy showed that the treatment of erythrocyte membranes with polyene antibiotic filipin produced more than twice as many filipin-cholesterol complexes in cholestatic cells as in control cells. The electron spin resonance studies on intact red blood cells, extracted membrane total lipids and phospholipids showed that the red blood cells in cholestasis were more fluid than those in control subjects. The increased susceptibility of erythrocyte membranes in cholestasis to phospholipase A2 is discussed on the basis of physicochemical properties of red cells. |
| Databáze: | OpenAIRE |
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