AGE-RELATED DEPLETION OF LINOLEIC-ACID DESATURATION IN LIVER-MICROSOMES FROM YOUNG SPONTANEOUSLY HYPERTENSIVE RATS

The present study was designed to investigate the microsomal interconv ersion of linoleic acid (LA) into arachidonic acid (AA) in young spont aneously hypertensive rats (SHR), in relation to the pathogenesis of h ypertension. Our results show lower Delta 6 and Delta 5 desaturase act ivities (the limiting steps in the bioconversion of LA into AA) in you ng SHR, as compared to Wistar Kyoto normotensive rats. This impairment of desaturase activities is raised when the blood pressure increases and is related to the age of animals. The fatty acid composition of li ver lipids shows a lower proportion of AA and a higher proportion of L A in SHR than in normotensive rats, confirming the depletion of the en zymatic system studied. Such a loss of desaturase activity may be unde r the control of hormones involved in the regulation of SHR blood pres sure.