Correlation of changes in rate of sterol synthesis with changes in HMG CoA reductase activity in cultured lens epithelial cells
In the present study, the authors correlated changes in HMG CoA reductase activity with changes in relative rates of sterol synthesis measured from either /sup 3/H/sub 2/O or 1-/sup 14/C-acetate for bovine lens epithelial cells cultured in the presence or absence of lipoproteins. Enzyme activity and rates of incorporation of /sup 3/H/sub 2/O or 1-/sup 14/C-acetate into digitonin precipitable sterols were measured in cells on the 4th day of subculture in DMEM containing 9% whole calf serum (WM) or 9% lipoprotein deficient serum (LDM). In three experiments, HMG CoA reductase activity (U/10/sup 6/ cells) averaged 2.2 +/- 0.1 times greater for cells grown in LDM than WM. Sterol synthesis averaged 3.0 +/- 0.4 times greater when measured with /sup 3/H/sub 2/O and 4.0 +/- 1.1 times greater when measured with /sup 14/C-acetate. Thus, /sup 3/H/sub 2/O and /sup 14/C-acetate appear to be comparable substrates for estimating changes in relative rates of sterol synthesis by cultured cells. The larger increases in rates of sterol synthesis than in reductase activity in response to decreased cholesterol could reflect stimulation at additional metabolic steps in the cholesterol pathway beyond mevalonic acid.
- Research Organization:
- Kirksville College of Osteopathic Medicine, MO
- OSTI ID:
- 6619347
- Report Number(s):
- CONF-8606151-; TRN: 87-020085
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
- Country of Publication:
- United States
- Language:
- English
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OXIDOREDUCTASES
ENZYME ACTIVITY
STEROLS
BIOSYNTHESIS
ACETATES
BIOLOGICAL PATHWAYS
CARBON 14 COMPOUNDS
CATTLE
CELL CULTURES
EPITHELIUM
LIPOPROTEINS
METABOLISM
SUBSTRATES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
WATER
ANIMAL TISSUES
ANIMALS
BODY
CARBOXYLIC ACID SALTS
DOMESTIC ANIMALS
ENZYMES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
MAMMALS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PROTEINS
RUMINANTS
STEROIDS
SYNTHESIS
TISSUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques