INVESTIGADORES
GIUSTO Norma Maria
artículos
Título:
Phospholipids and acylglycerols biosynthesis and 14CO2 production from 14C-glycerol in the bovine retina: the effects of incubation time, oxygen and glucose
Autor/es:
BAZÁN, N.; GIUSTO, N.M.
Revista:
EXPERIMENTAL EYE RESEARCH
Editorial:
ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD
Referencias:
Año: 1979 vol. 29 p. 155 - 168
ISSN:
0014-4835
Resumen:
When the entire bovine retina was incubated in 95 μm [U-14C]glycerol,
the precursor penetrated the tissue and it was used for the de novo
biosynthesis of glycerolipids. A minor proportion of the labeled
glycerol turned to 14CO2. The following labeling
sequence was suggested: glycerol phosphorylation, double acylation,
phosphatidate, diacylglycerol and triacylglycerol. Under aerobic
conditions, a remarkable channelling of the label towards
triacylglycerol biosynthesis was found. Comparatively, much lower
specific activities were encountered in all the phosphoglycerides,
phosphatidylinositol biosynthesis attaining the highest rate. At an
early incubation time, the peak labeling of total phosphoglycerides was
closely followed by phosphatidate radioactivity. The phosphoglyceride
content slightly decreased in retinas incubated in the absence of added
glucose. Anoxia, however, resulted in a diminution of the concentration
of the diacylglycerophosphatides of choline and of ethanolamine and in a
significant increase of their monoacyl derivatives. In an incubation
medium devoid of glucose, the specific activity in the diacyl and
monoacylglycerophosphatides of choline and ethanolamine was
significantly raised. Furthermore, there was a dramatic decrease in the
triacylglycerol biosynthesis without modification of glycerol
incorporation in the polar lipids and augmented the labeling in the
lipid-free tissue residue. Anoxia abolishes the uptake of glycerol in
retina lipids.