title: Effect of gamma irradiation on alpha-tocopherol levels in ruminant blood samples.
abstract: Quantification of circulating levels of vitamin E in free-ranging species can provide useful guidelines for evaluating nutrient status in captive exotic animals. Under current USDA regulations, ruminant plasma or serum samples must be subjected to 1) live-animal testing and viral screening, or 2) gamma (gamma-) irradiation prior to importation. Because irradiation is known to promote free radical formation and destruction of alpha-tocopherol in various tissues, these studies were conducted to evaluate the effect of irradiation on ruminant blood fractions with and without added antioxidant. alpha-tocopherol levels were measured in paired (irradiated vs. unirradiated) plasma or serum samples collected from zoo ruminants (n = 8 spp.). Irradiation caused highly significant (P less than 0.001) but inconsistent destruction of alpha-tocopherol. Addition of 10% volume of a 1% pyrogallol solution to plasma or serum protected against alpha-tocopherol deterioration during gamma-irradiation. In order to ensure valid comparative values for vitamin E studies while complying with USDA regulations, it is recommended that plasma or serum samples collected from ruminants outside the US be treated with antioxidant prior to importation.
authors.affiliation: Animal Health Center, New York Zoological Society, Bronx 10460.
authors.forename: E S
authors.initials: ES
authors.lastname: Dierenfeld
authors.forename: J T
authors.initials: JT
authors.lastname: McGuire
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D003670:Deer / Q000097:blood; D005720:Gamma Rays; D009752:Nutritional Status; D011748:Pyrogallol / Q000494:pharmacology; D012418:Ruminants / Q000097:blood*; D012756:Sheep / Q000097:blood; D014810:Vitamin E / Q000097:blood / Q000528:radiation effects*
chemical_list: D000975:Antioxidants; D011748:Pyrogallol; D014810:Vitamin E