Metabolism of lipid labeled very low density lipoprotein from laying turkey hens in laying turkey hens and immature turkeys.

Labeled very low density lipoprotein of laying turkey hens (VLDL-L) was prepared by injecting 1-14C-palmitate abd subsequently isolating the VLDL-L by ultracentrifugation at d=1.006. The isolated VLDL-L then was injected into recipient laying hens, immature males, or immature females. Size exclusion chromatography of recipient laying hen plasma showed no remnant particles of smaller size or greater density than the injected VLDL-L up to 400 min postinjection. In the immature birds of either sex, remnant particles of greater density and smaller size than the injected VLDL-L were present when blood samples were withdrawn at 5 (males) or 1 (females) min postinjection. In laying females, both VLDL-L-triglyceride (VLDL-L-TG) and phospholipids (VLDL-L-PL) had identical fractional clearance rates of .00253 min-1 and had parallel rates of disappearance. The irreversible loss of VLDL-L-TG was 12.8 g/day while it was 4.8 g/day for VLDL-L-PL. Thirty-one percent of the injected radioactivity was isolated in ovarian follicles undergoing rapid development. VLDL-L-TG decayed with a single exponential decay component in both immature males and females, but decayed more rapidly in the males; it also decayed more rapidly in the immature birds of both sexes than in laying females. There was also an increase in triglyceride (TG) radioactivity in lipoproteins of d greater than 1.006. The VLDL-L-PL decayed in a more complex pattern in the immature birds, showing more than a single exponential decay component. There was also an increase in phospholipid (PL) radioactivity in lipoproteins of d greater than 1.006. THe VLDL-TG and PL radioactivities did not decay in a parallel pattern in immature birds where remnant particles of d greater than 1.006 were present soon after lipid labeled VLDL-L injection.