Alteration in membrane lipid packing/organization induced by chronic ethanol ingestion
The effect of chronic ethanol on lipid packing and organization was investigated using exogenous phospholipase A/sub 2/ (Crotalus durissus terrificus). Liver microsomal membrane lipids from chronic ethanol fed rats were found to be hydrolyzed at a significantly reduced rate compared to the control although fluorescent probes did not show a difference in lipid order. The reduced activity was also found against liposomes made from extracted phospholipids although to a lesser extent. Thus, although the key component causing the resistance to hydrolysis is a phospholipid, the organization of the membrane is also important. Endogenous phospholipase A/sub 2/ activity was also determined and in contrast to the exogenous phospholipase A/sub 2/, the ethanol altered membranes had a higher level of activity compared to the control. These results suggest that the activity of the exogenous and endogenous phospholipases A/sub 2/ are controlled by different mechanisms. It appears that the exogenous phospholipase A/sub 2/ detects bilayer packing and organizational changes caused by the chronic ethanol whereas the endogenous enzyme itself appears to be modified by the ethanol treatment in a manner which overcomes or is independent of the influence of the lipid bilayer packing and organization.
- Research Organization:
- Thomas Jefferson Univ., Philadelphia, PA
- OSTI ID:
- 6060754
- Report Number(s):
- CONF-870644-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ETHANOL
BIOLOGICAL EFFECTS
LIPASE
ENZYME ACTIVITY
LIPIDS
METABOLISM
CELL MEMBRANES
CHRONIC EXPOSURE
FLUORESCENCE
INGESTION
LIPOSOMES
LIVER
MICROSOMES
RATS
ALCOHOLS
ANIMALS
BODY
CARBOXYLESTERASES
CELL CONSTITUENTS
DIGESTIVE SYSTEM
ENZYMES
ESTERASES
GLANDS
HYDROLASES
HYDROXY COMPOUNDS
INTAKE
LUMINESCENCE
MAMMALS
MEMBRANES
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
RODENTS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology