732 VII. LIPID DISTRIBUTION IN SPECIFIC TISSUES 



triphosphatase) activity on activation with Mg. It is believed that this 

 preparation is identical with the ATPase in the Kielley-Meyerhof system. 

 However, it differs from myosin ATPase, which is localized in the isolated 

 myofibrils. 



In addition to the lipids normally noted in other tissues, several alde- 

 hydes are also contained in muscle. Thus, Klenk and co-workers 194 

 isolated a mixture of Ch, Cie, and Cis aldehydes, in the form of the dimethyl 

 acetals, from the phospholipids of horse muscle and beef heart, as well as 

 A 9 -octadecenal. However, no A n -octadecenal was detected, although this 

 is known to be a component of brain phosphatides. These plasmalogens, 

 as they are called, were found to account for 6.5% of the total phospholipids 

 of swine heart. 40 In a later study, Klenk and Gehrmann 195 reported that 

 the plasmalogens of beef heart are concentrated in the lecithin fraction, and 

 that only a relatively minor proportion are present in the several cephalin 

 fractions. 



Different lipid patterns have been found in the conductive and connec- 

 tive tissues of beef heart, as contrasted with the heart muscle. One im- 

 portant variation reported by Mallov, McKibbin, and Robb 196 was in the 

 cerebroside content, which was 0.01 to 0.02% of the fresh weight in the 

 heart muscle, and 0.03% of the fresh weight in the conducting tissue of this 

 organ. 



{2) The Effect of Species on the Composition of Muscle Lipids 



Bloor and Snider, 197 and later Bloor alone, 190 recorded the lipid composi- 

 tion of the different types of muscle from a wide variety of animals. Table 

 3 gives the average figures for the lipids in the various types of muscle from 

 different groups of animals, while Table 4 furnishes individual data on a 

 large number of animals. Table 5 is a summary of the phospholipid and 

 cholesterol content of the different types of muscle of various species of 

 birds and of cold-blooded animals (see pages 734, 735). 



Several other studies have been macte of muscle composition. One of 

 these is reported by Javillier et al., 179 who cited the following figures for 

 phospholipids (expressed in percentage of moist weight), pigeon, 2.4%; 

 horse, 1.7%; guinea pig, 1.5%; frog, 1.2%; and rat, carp, and dogfish, each 

 1.1%. 



194 E. Klenk, W. Stoffel, and H. J. Eggers, Z. physiol. Chem., 290, 246-251 (1952). 

 196 E. Klenk and G. Gehrmann, Z. physiol. Chem., 292, 110-117 (1953). 

 196 S. Mallov, J. M. McKibbin, and J. S. Robb, J. Biol. Chem., 201, 825-838 (1953). 

 ' 97 W. R. Bloor and R. H. Snider, /. Biol. Chem., 107, 459-470 (1934). 



