Animal endogenous triglycerides: II. Rat and chicken adipose tissue

The endogenous adipose tissue triglycerides of rat and chicken differ markedly in composition from those of swine although all three contain the same major fatty acids. The main difference is that the swine triglycerides have saturated fatty acids in the middle position, whereas in rat and chicken that position is preferentially occupied by unsaturated acids. In swine adipose tissue triglycerides the order of preference for the middle position is 16∶0>16∶1>18∶0>18∶1, whereas in rat and chicken triglycerides the order is 18∶1>16∶1>18∶0>16∶0. Generalizing, in swine the order of preference for the 2 position is chain length over unsaturation, shorter chains over longer chains, and saturation over unsaturation. In rat and chicken, the degree of unsaturation prevails over chain length, longer chains over shorter chains, and unsaturation over saturation.