Cardiac lipids

B22. Buffon, A., Santini, S. A., Ramazzotti, V., Rigattieri, S., Liuzzo, G., Biasucci, L. M., Crea, F., Giardina, B., and Maseri, A., Large, sustained cardiac lipid peroxidation and reduced antioxidant capacity in die coronary circulation after brief episodes of myocardial ischemia. J. Am. Coll. Cardiol 35, 633-639 (2000). 

Results from this study showed that SOD activity was not affected by acute ADR treatment. A second finding was that acute ADR toxicity did not promote cardiac lipid peroxidation. However, it was observed that mitochondrial lipid peroxidation was highest in mice fed diets low in both antioxidants. Ultrastructural examination revealed mitochondrial abnormalities in cardiac tissue from ADR-treated animals (Figures 3 and 4). There were large vacuoles within the mitochondria and condensation of the inner and outer membranes of the mitochondria. The ultrastructural effects of ADR treatment were most severe in the low E, Mn-deficient mice. It is reasonable to suggest that a higher than normal level of lipid peroxidation may predispose the animal to tissue damage from ADR. Consistent with this concept, Meyers et al. (34) have reported that pretreatment with supplemental vitamin E can reduce the toxicity of ADR in mice. 

J. Suzuki, W.-J. Shen, B.D. Nelson, S. Patel, J.H. Veerkamp, S.P. Selwooii, G.M. Murphy, E. Reaven, and F.B. Kraemer, Absence of cardiac lipid accumulation in transgenic mice with heart-specific HSL overexpression. Am. J. Physiol. Endocrinol. Metab., 2001, 281, 857-866. 

In summary, our results define an important role for PPARa in the maintenance of cellular lipid and glucose homeostasis in vivo via the transcriptional control of target genes encoding mitochondrial and extra-mitochondrial fatty acid oxidation enzymes. We also demonstrate that gender-related mechanisms are involved in hepatic and cardiac lipid metabolism. Lastly, we propose that the PPARa -/- mouse may prove useful as a model of human diseases due to inborn and acquired alterations in cellular lipid metabolism. 

Values given in parentheses represent the total cardiac lipids measurements rather than that of the cardiac TG, which were not reported. 

The lipid content in pig hearts normally is approximately 2%, which is similar to that observed in rat hearts. Little is known about the cardiac lipid content of monkeys fed a low fat control diet. These species respond differently to experimental diets which contain high levels of fat and are rich in docosenoic acid. In the rat and pig studies (Fig. 1) HEAR oils were fed which contained erucic acid (22 1 n-9). In some of the monkey studies fish oils were fed which contained cetoleic acid (22 1 n-11) as the main docosenoic acid isomer. The results from both 22 1 isomers are combined because of their similarity in response. 

Fig. 1. The concentration (mg/g wet weight) of the total cardiac lipids and the cardiac triglycerides of rats, pigs, and monkeys fed a low fat control diet (time 0) and diets to which a control oil (first bar) or a docosenoic acid containing oil (second bar) was added. The portion of triglycerides in the total lipids are indicated by a hatched bar wherever this information is available. Source of data rat (Kramer and Hulan, 1978 Kramer et al., 1979) pig, 1.4 weeks (Opstvedt et al., 1979), all other values (Kramer et a/., 1975) and monkey, 1 and 10 weeks (Beare-Rogers and Nera, 1972), all other values (Ackman, 1980). Erucic acid was the docosenoic acid in all studies except the monkey data from Ackman (1980) who fed partially hydrogenated fish oil containing mainly cetoleic acid.

On the other hand, the total cardiac lipid content of the pig is not affected by high fat diets, even when the diets contain 22 1. The cardiac triglycerides also remain unaffected by diets with or without 22 1 (Fig. 1, time period 1.4 weeks for pigs). 

The cardiac lipids of monkeys appear to increase when they are fed diets rich in fat. This is evident from the results of the total heart lipids of... 

These results appear to indicate that cardiac lipids of the pig do not respond to the feeding of high fat diets with or without docosenoic acids. The rat, on the other hand, after the initial acute myocardial lipidosis, appears to adapt after about 1 week to dietary docosenoic acids. The monkey does not appear to adapt well to high fat diets however, docosenoic acids do not appear to have any additional effects on total heart lipids or heart triglycerides. 

Dietary docosenoic acid (22 1) is incorporated into the cardiac lipids of rats, pigs, and monkeys. When diets containing similar concentrations of 22 1 are fed to these three species, the rat accumulates the greatest amount... 

Concentration of C22 n-3 Polyunsaturated Fatty Acids in the Cardiac Lipids of Rai, Pig, and Monkey... 

Cardiac Lipid Changes in Rats, Pigs, and Monkeys Fed High Fat Diets... 

III. Changes In Cardiac Lipids of Rats Fed Different Oils and Fats. . . 478... 

IV. Changes in Cardiac Lipids of Pigs and Monkeys Fed Different Oils and Fats and How These Changes Compare to Those Observed in... 

When one is designing experiments to test the nutritional and toxicological properties of vegetable oils, each fatty acid should be examined by itself. However, such studies would be too costly and furthermore complicate the issue since some fatty acids would be poorly absorbed and others would promote essential fatty acid deficiency. Therefore, it seems appropriate to consider cardiac lipid changes in animals fed diets which contain different vegetable oils or fats that in fact possess a characteristic fatty acid composition (Table I). A knowledge of the differences in cardiac lipids with different dietary fats and with different animal species may help us to understand the causes of this cardiopathological condition. 

III. CHANGES IN CARDIAC LIPIDS OF RATS FED DIFFERENT OILS AND FATS... 

It is apparent from the results presented in Table XX that the amount of total cardiac fat in pigs is the same irrespective of the level or type of fat in the diet. For example, a basal diet with no added fat results in a similar cardiac lipid content as a diet that contains corn, soybean, LEAR, HEAR, or fish oils. The level of fat in the heart may be different between breeds of pigs, but within an experiment the level of cardiac fat remains constant with diet and time on experiment (Table XX). In this respect, the pig differs from the rat which shows a marked increase in cardiac TG with dietary 22 1 (Fig. 1). The docosenoic acid content in the cardiac lipids of the pig remains relatively low compared to the cardiac lipid of the rat fed a diet containing a similar content of docosenoic acid (see Fig. 2, Chapter 14). 

The cardiac lipid content of monkey (Macaca fascicularis) appears to be the same irrespective of the kind of dietary fat or oil, even with diets rich in docosenoic acid (Table XXI). There is one exception in a 6 month study reported by Ackman (1980) in which the lard/corn oil control diet gave an unusually low cardiac lipid value. However, this result needs to be confirmed, since in an earlier study by the same author there was no difference in the cardiac lipid content (Ackman and Loew, 1977). Except for this one... 

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