Whole-body localization of 14C-tocopheryl acetate in the rat following oral administration.
The whole-body localization of dl-alpha-[3, 4-14C2]-tocopheryl acetate was examined in the rat for intervals ranging between 12-96 hr following administration of a single oral dose. Quantitative evaluation of the macroautoradiograms revealed a rapid removal of 14C-vitamin E equivalents from the blood and gut and their accumulation in body tissues. When the densitometric data were expressed as dpm/mm2, the values for radioactivity uptake by the adrenal cortex were systematically the highest of all tissues examined for all time periods. At 12-96 hr after dosing, high activity was noted in spleen, bone marrow, liver, lymph nodes and fat; moderate activity was observed in myocardium, lung, gastric mucosa, pituitary, blood, hair follicles, Harder's gland and nasal mucosa; low values were found in brain, skeletal muscle and spinal cord. The nearly complete exclusion of radiovitamin E from the brain and its localization to the choroid plexus implied the operation of a blood-brain barrier. Labeled vitamin E uptake in brain, salivary glands and skeletal muscle was essentially linear and increased with time over 12-96 hr. For both early and late sacrifice periods, a differential pattern of 14C-radioactivity uptake was observed with the pituitary, where the pars nervosa exhibited 2.8 times greater activity than the pars distalis. The significance of the findings is discussed in relation to the suggested role of vitamin E in pituitary-adrenal functions, hemopoiesis and oral physiology.
D000284:Administration, Oral; D000302:Adrenal Cortex / Q000378:metabolism; D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D010913:Pituitary-Adrenal System / Q000502:physiology; D051381:Rats; D013997:Time Factors; D014018:Tissue Distribution; D024505:Tocopherols; D014070:Tooth / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism / Q000502:physiology; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
D014810:Vitamin E; D024502:alpha-Tocopherol; D024505:Tocopherols