Modulation of phosphatidic acid metabolism by insulin in cerebral cortex synaptosomes

SALVADOR, GABRIELA ALEJANDRA; PASQUARÉ, SUSANA; ILINCHETA, MÓNICA; ZULIAN, SANDRA; MATEOS, MELINA VALERIA; GIUSTO, NORMA MARÍA

New York City

Congreso; Thirty-Fifth Annual Meeting of the American Society for Neurochemistry; 2004

Besides of de novo biosynthesis phosphatidic acid (PA) can be generated either by phosphatidylcholine (PC) hydrolysis through phospholipase D (PLD) or diacylglycerol (DAG) phosphorylation through diacylglycerol kinase activity (DAGK). Additionally PA can be further hydrolyzed by phosphatidate phosphohydrolase (PAP) yielding DAG. We have previously described that PLD/PAP/DAGK pathway was present in cerebral cortex (CC) synaptosomes and it was strongly affected by aging. Our purpose was to study the effect of insulin on PLD/PAP/DAGK pathway in CC synaptosomes from adult (3–4 m) and aged (26–28 m) rats. The effect of the hormone was evaluated as a time function. At 5 min incubation, Insulin stimulated both PLD and DAGK activities, whereas PAP2 was inhibited. At 30 min incubation Insulin effect was lower than at 5 min incubation. In synaptosomes from aged rats, we could not observed the stimulatory effect of insulin on PLD and DAGK activities. These findings suggest the modulation of PA generation by insulin and its different modulation during the aging process.