FAT AND .MITOCHONDRIA IN CARDIAC MUSCLE 6 



They interpreted this apparently normal action of the heart, in 

 the presence of a marked fatty change, as due to the very large 

 reserve force of the cardiac fibers. Pratt ('04) concluded that 

 there is^ no evidence to support the once commonly accepted 

 theory that fatty metamorphosis of the heart muscle is often 

 the cause of myocardial insufficiency. Many other observers 

 have arrived at similar conclusions and nearly all now agree with 

 the view advanced by Rosenfeld ('01) and Herxheimer ('02) 

 that the fat in so-called fatty degeneration or metamorphosis is 

 in reality of infiltrative, not degenerative origin. Of importance 

 in this connection are the observations of Lambert ('14) upon 

 tissue cultures of the chick heart. He finds that the source 

 of the fat in the embryonic muscle cells is the medium in which 

 the cells grow and that the fat droplets are not the result of cell 

 degeneration. 



Referring especially to fat in the heart, Malloiy ('14) has re- 

 cently well expressed the view now held by most pathologists : 



The fat makes its appearance in visible form because of diminished 

 utilization (oxidation) of the fat normally brought to the muscle cyto- 

 plasm. The fat accumulates as the result of two different causes, (a) 

 disturbances of nutrition and (b) toxemia. The accumulation of fat 

 in the cji:oplasm of the muscle-fibers has of itself little significance. 

 It may in time unquestionably be utilized and removed. Its im- 

 portance pathologically lies in the evidence its presence gives of dis- 

 turbed cell metabolism and in its frequent association with necrosis. 



Ostertag ('89), Ricker and Ellenbeck ('99), Fibiger ('01), 

 Arnold ('03), Keinath ('04) and Babes ('08) have referred to the 

 isolated occurrence of visible fat in the apparenth' normal cardiac 

 fibers of certain species or individuals either without advocating 

 or without offering sufficient proof that fatty droplets are of usual 

 occurrence in this situation. 



Hofbauer ('05) describes visible fat in normal human fetal 

 heart muscle. Bell ('11) was the first to show clearly that visible 

 fat ('liposomes') is normally present in the cardiac muscle of the 

 common laboratory mammals. He also demonstrated that the 

 quantity of visible fat is increased when fatty foods are given and 

 decreased when animals are starved. Bell's work, as well as my 

 own observations in confirmation of his results ('12 a), had ref- 



