MYOCARDIAL LIPID-COMPOSITION IN TURKEYS WITH DILATED CARDIOMYOPATHY

Objective: The aim was to determine if reduced heart lipid peroxidatio n in turkeys with two forms of dilated cardiomyopathy, previously repo rted, was related to an alteration in the lipid composition of the ven tricle. Methods: Myocardial lipid composition was measured in turkeys with two types of dilated cardiomyopathy. Twenty six turkeys with natu rally occurring dilated cardiomyopathy, six with furazolidone induced dilated cardiomyopathy, and 18 age matched control birds were used at 1 day, 9-10 days, and 38-78 days of age. Left ventricular fatty acid c omposition of the phospholipid, triglyceride, free fatty acid, and cho lesterol eater fractions was analysed using gas chromatography. Result s: Significant age related changes were identified in the fatty acid c omposition of the heart. In the phospholipid fraction, linoleic acid ( 18:2 omega 6) values increased with age, while arachidonic acid values decreased. The saturated to unsaturated fatty acid ratio in control h earts was unchanged as a function of age in the phospholipid fraction. In the triglyceride fraction, however, this ratio decreased substanti ally between newly hatched and nine day old birds and then markedly in creased in two month old controls. There was a striking alteration in the saturated to unsaturated fatty acid ratio in the triglyceride frac tion of 2 month old cardiomyopathic birds; this ratio was markedly inc reased in the furazolidone induced cardiomyopathic turkey hearts (5.14 v 2.79 in controls) and markedly diminished (ie, 0.97 to 1.21) in the spontaneously cardiomyopathic turkeys. A significant increase in myri stic (14:0) and decrease in linoleic (18:2 omega 6) acid concentration in the furazolidone group v control and a marked decrease in myristic and increase in linoleic acid concentrations in the spontaneously car diomyopathic group v controls was present. Conclusions: (1) There is a n age related alteration in the fatty acid composition of control turk ey hearts. (2) Previously identified reduced lipid peroxidation in fur azolidone induced and spontaneous cardiomyopathy in turkeys does not a ppear to be related to reduced concentration of polyunsaturated fatty acids. (3) The two forms of dilated cardiomyopathy are associated with markedly disparate alterations in the concentration of polyunsaturate d fatty acids in the triglyceride fraction of 1-2 month old turkey hea rts. The changes may be related, in part, to the pathogenesis in these two different forms of dilated cardiomyopathy.