CHANGES IN TISSUE POLYUNSATURATED FATTY-ACIDS WITH AGE, IN SPONTANEOUSLY HYPERTENSIVE RATS

The relationship between the biosynthesis of long chain fatty acids an d their distribution in the key organs of hypertension is of considera ble interest because of their role in the production of vasoactive eic osanoids and their effects on membrane properties. The present study a nalyzed the fatty acid compositions of the total lipids in the kidney, aorta, heart, and hepatocytes of 1-, 3-, and 6-mon-old spontaneously hypertensive rats (SHR) and their normotensive controls, Wistar Kyoto rats (WKY) by capillary gas chromatography. The major changes concerne d the polyunsaturated fatty acids (PU FA). The percentage of arachidon ic acid (AA) was significantly greater in the 1-mon-old SHR kidney tha n in the WKY kidney, but it was lower at 3 and 6 mon. The percentage o f eicosapentaenoic acid was very low in the SHR kidney. The results fo r the aorta were similar, with marked decreases in 18:2n-6 and 18:3n-3 in SHR aged 1 and 6 mon. Despite a higher proportion of 18:2n-6 and A A at 6 mon, there was no major change in the SHR heart lipids. The fat ty acid spectrum in the liver provides additional evidence for the pre viously reported inhibition of desaturase activities in SHR. Thus, thi s study shows that the PUFA composition is modified differently in dif ferent tissues in SHR, and this may be related to the pathogenesis of hypertension in these animals.