Abstracto

PerturbationOfDesaturase-AndElongase-CatalyzedEquilibrium Between FattyAcids In LiverAnd PlasmaTriglyceridesAnd hospholipids Of Streptozotocin (Type 1)AndGoto-Kakizaki (Type 2)DiabeticRats

Willy J.Malaisse, Ying Zhang, Berrin Oguzhan, Karim Louchami, Hassan Jijakli, Philippe Courtois, Abdullah Sener, Laurence Portois, Yvon A.Carpentier

The fatty acid content and pattern of plasma and liver lipids were recently characterized in fed and overnight starved normal and Goto- Kakizaki rats(GK), as well as fed streptozotocin-induced diabetic animals (STZ). The present report deals with the desaturase- and elongasecatalyzed equilibrium between selected fatty acids in plasma unesterified fatty acids, phospholipids and triglycerides and liver phospholipids and triglycerides of the same animals. Attention is drawn inter alia to the higher activity of both 9-desaturase and elongase and the more efficient stepwise conversion of C18:26 to C20:46 in GK rats than in STZ rats. Moreover, significant correlations were found between the liver and plasma values for the C16:0/C16:17, (C16:0+C16:17)/(C18:0 +C18:19), C18:33/C20:53, C20:53/C22:53 and C22:53/ C22:63 ratios in triglycerides, as well as the C18:0/C18:19, (C16:0 +C16:17)/(C18:0+C18:19), C20:53/C22:53 and C22:53/ C22:63 ratios in phospholipids. These findings indicate that, in several respects, the apparent equilibrium values for the interconversion of selective fatty acids in liver phospholipids and triglycerides can be reliably judged from the corresponding values found in circulating lipids.