FISHERY BULLETIN: VOL, 69, NO. 2 



rats increasingly higher concentrations of lin- 

 olenicacid (18:3co3) increases the concentration 

 of the fatty acids of the &;3 family in the liver 

 and that the proportion of the fatty acids of 

 the oleic (18:1 w9) and linoleic (18:2 coG) fam- 

 ilies are concomitantly reduced. They hypothe- 

 size that this interaction is due to the compe- 

 tition for enzymes necessary for elongation and 

 desaturation within the individual families of 

 fatty acids. 



Since our pig e.xperiment included an in- 

 creasing quantity of 18:3 coS in the diet, the 

 question arose as to whether this hypothesized 

 competitive interaction actually occurred. 



Trial II results were analyzed by correlation 

 analysis and polynomial regression analysis as 

 previously described. The quantity of men- 

 haden oil consumed constituted the X axis, and 

 the quantity of the 17:1 o)9 or 18:2 co6 family 

 fatty acid in question the Y axis. 



The 0)3 family fatty acids incorporated into 

 the diet of the pigs as menhaden oil and sub- 

 sequently ingested resulted in a significantly 

 depressed deposition of the quantity of certain 

 members of the w6 and c<j9 families of fatty 

 acids. The mechanism involved, according to 

 the accepted hypothesis, is that the parent fatty 

 acids of the various fatty acid families trigger 

 a highly competitive mechanism for the meta- 

 bolic enzymes of the systems of carbon-chain 

 elongation and dehydrogenation. Successful 

 comijetition for the enzymes depends upon an 

 affinity preference (aj3, co6, and co9) and upon 

 the relative concentration of the various fatty 

 acids, or upon both affinity and concentration. 

 These results agree in part with the experi- 

 mental evidence (Mohrhauer and Holman, 

 1963a) whereby the feeding of increasing levels 

 of one of the parent acids or other members 

 of a family results in an accumulation of acids 



Table 24. — Liver tissue — comparison of correlation coefficients and significant degree of poljTiomial regression 

 obtained by relating the quantity of menhaden oil consumed (.Y) until the pigs attained body weights of 90.9, 

 79.5, or 68.0 kg to the amount of individual fatty acids deposited in liver tissue (F). 



;• <.03 



p <.oi 



298 



