The Lecithin, Cephalin, and Sphingomyelin Contents of Plasma and Liver of the Fowl; Their Metabolic Interrelations as Shown by the Administration of Diethylstilbestrol

In 1944, Taurog et al. (1) pointed out that practically all of the phospholipides in plasma of man and dog contain choline. This indicates that the plasma phospholipides of these two species consist almost entirely of lecithins and sphingomyelins. Confirmation of this finding has now come from Hack (2) and from Sinclair (3-5). The former reported that about 95 per cent of the phospholipides in the serum of normal human subjects are choline-containing and Sinclair found that 3 to 8 per cent of the plasma phospholipides in man, dog, beef, and pig are cephalins. The composition of plasma phospholipides of the bird differs, however, from that of the mammal. Thus, Flock and Bolhnan (6) reported that only 53 per cent of the plasma phospholipides of the domestic fowl are choline-containing, whereas Sinclair (3-5) has shown that in turkey serum no more than 80 per cent of the phospholipides are of this type. By combining two methods, (1) that developed by Taurog et al. (7) for separating choline-containing and non-choline-containing phospholipides by permanent adsorption of the latter upon MgO and (2) that of Schmidt et al. (8), based on the selective destruction of lecithins in a solution of choline-containing phospholipides, it became possible to measure separately the concentrations of lecithins, cephalins, and sphingomyelins in tissues. These methods were used in an earlier study dealing with dog tissues (9) and in the present investigation they have been applied to a study of plasma phospholipides of the domestic fowl. In order to investigate further the metabolic significance of the three types of phospholipides found in the bird, the plasma of the domestic fowl injected with stilbestrol was also examined. This procedure has been shown to induce a lipemia not only in the non-laying female bird but also in the male bird (10).