Aged-as¬sociated changes in the content and fatty acid composition of brain glycerophospholipids

LÓPEZ, G.H.; ILINCHETA DE BOSCHERO, M.G.; CASTAGNET, P.I.; GIUSTO, N.M.

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART B, BIOCHEMISTRY & MOLECULAR BIOLOGY.

ELSEVIER SCIENCE INC

Año: 1995 vol. 112 p. 331 - 343

1096-4959

The fatty acid composition of total lipids and individual phospholipids and the ratio ofcholesterol-to-phospholipid content were studied in cerebral cortex, subcortical white matter,cerebellum and medulla oblongata/pons in 4-, 21.5- and 28-month-old rats. Thecholesterol-to-phospholipid molar ratio in subcortical white matter, medulla oblongata/pons andcerebellum in 28-month-old rats was found to be 17, 17 and 16% higher, respectively, than inadult rats. These alterations in the molar ratio were produced as a result of a net increase incholesterol content rather than by changes in the total phospholipid content. The content ofalkenylacylglycerophosphoethanolamine (alkenylacyl GPE) increased in 28-month-old rats withrespect to 4-month-old rats, following the order cerebral cortex > cerebellum > medullaoblongata/pons > subcortical white matter. The fatty acid composition of total lipids showed anincrease in monounsaturated fatty acids (MUFA) and a decrease in polyunsaturated fatty acid(PUFA) content with increasing age in all regions studied, such changes being more marked incerebellum, medulla oblongata/pons and subcortical white matter than in cerebral cortex. Theproportion of 22:6(n-3) in cholinegiycerophospholipids in the different brain regions of28-month-old rats showed a slight decrease with respect to that in adult rats following the ordercerebellum > medulla oblongata/pons > subcortical white matter, whereas that of 20:4(n-6)decreased only in cerebellum. Ethanolaminegiycerophospholipid fatty acid composition wasmodified in 28-month-old rats through a marked increase in monounsaturated fatty acids(18: l(n-9) and 20: l(n-9) specifically) in all brain areas. The MUFA content of alkenylacyl GPEincreased with increasing age in all the regions studied, in the order cerebral cortex > medullaoblongata/pons > subcortical white matter > cerebellum. An increase in the MUFA content ofdiacylgiycerophosphoethanolamine was observed in medulla oblongata/pons and cerebellum ofaged rats with respect to control rats. PUFA content of alkenylacyl GPE decreased mainly inmedulla oblongata/pons, cerebral cortex and subcortical white matter of aged rats. The PUFAcontent of serineglycerophospholipids was the most affected by aging. Changes occurred mainlyin the content of 22: 6(n-3), 22: 4(n-6) and 20: 4(n-6) in cerebellum and of 22: 6(n-3) and 22: 4(n-6) in subcortical white matter. Changes in the inositolglycerophospholipid fatty acid content of28-month-old rats were observed mainly in medulla oblongata/pons, which showed a decrease inPUFA (22: 4(n-6) and 22: 6(n-3)) content and an increase in MUFA (18:1 and 20:1).