Membrane bilayer instability and the pathogenesis of disorders of myelin.
We have previously shown that total lipid extracts from normal nervous tissues spontaneously form a structure in vitro resembling the cell membrane bilayer, but only at a critical temperature, T*, equal to the 'physiological' temperature of the original tissues. In the present study, we found T* for normal human myelin lipids was 37 degrees C, in agreement with the concept that lipid metabolic pools maintain a critical composition in vivo which permits spontaneous formation of the (myelin) membrane bilayer at normal body temperature. But T* for myelin lipids from a patient with metachromatic leukodystrophy was less than 30 degrees C. Thus, myelin lipid composition was inappropriate for normal bilayer stability at this patient's core temperature, suggesting a mechanism whereby defective lipid metabolism in this disease could produce pathological myelin. The shift in T* in this patient was unlikely to be simply secondary to myelin destruction, as myelin lipids from a patient with advanced multiple sclerosis yielded a normal value for T* of 37 degrees C, even when extracted from areas of extensive demyelination.
Ginsberg
L
L
Labortory of Physical Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892.
Gershfeld
N L
NL
D000328:Adult; D001921:Brain / Q000473:pathology; D006801:Humans; D007966:Leukodystrophy, Metachromatic / Q000473:pathology*; D008051:Lipid Bilayers / Q000737:chemistry*; D009103:Multiple Sclerosis / Q000473:pathology*; D009186:Myelin Sheath / Q000737:chemistry; D013696:Temperature
D008051:Lipid Bilayers