Antioxidant systems of the avian embryo: tissue-specific accumulation and distribution of vitamin E in the turkey embryo during development

1. Tissue-specific accumulation of tocopherols and tocotrienols in turkey t issues during embryonic development and their susceptibility to lipid perox idation were investigated. 2. Fertile turkey eggs were incubated using standard commercial conditions. Embryonic tissues were collected at 16, 22, 25 d of incubation and from da y-old poults (referred to as day 29) and alpha-; beta-+gamma- and delta-toc opherols and respective tocotrienols were analysed by HPLC. 3. A turkey diet provided to the parent hens contained the complete range o f tocopherols and tocotrienols. Between days 16 and 22 of embryo developmen t, the alpha-tocopherol concentration in the liver remained constant and th en increased significantly (P<0.01) reaching a maximum just after hatching Similar changes were observed for the other tocopherols and tocotrienols. 4. The accumulation of alpha-tocopherol in the yolk sac membrane (YSM) star ted after day 20 of development and at hatching the alpha-tocopherol concen tration in the YSM was twice that of beta-+gamma-tocopherols and 15 times g reater than that of alpha-tocotrienol. 5. In the kidney, heart, lung muscle and adipose tissues a gradual increase in tocopherol and tocotrienol concentrations took place between days 20 an d 25 of development with a sharp increase in particular of alpha-tocopherol between days 25 and 29. There was a discrimination between tocopherols and tocotrienols during their assimilation from the diet by the parent hen and during metabolism by the developing turkey embryo. 6. Tissue-specific features in the susceptibility to lipid peroxidation wer e found with the brain being the most susceptible to lipid peroxidation at day 25 and in day-old poults.