The effects of dietary vitamin E and selenium deficiencies on plasma thyroid and thymic hormone concentrations in the chicken.
Beginning at hatching, male Cornell K strain single comb white leghorn chickens were fed a basal diet, with or without vitamin E (100 IU/kg) and/or selenium (Se, 0.2 ppm). After 3 weeks of treatment, animals fed either the Se-deficient or basal diet had significantly reduced plasma Se-dependent glutathione peroxidase activities when compared to those fed a vitamin E and Se-supplemented diet. Similarly, animals fed the vitamin E-deficient or basal diet had significantly reduced plasma alpha-tocopherol levels. The effect of these treatments on plasma concentrations of thyroid hormones (T(3)/T(4)), growth hormone (GH), and thymic hormone (thymulin) was determined using radioimmunoassay and ELISA. A deficiency in Se, but not in vitamin E, resulted in an increase in plasma T(4) concentrations while plasma T(3) concentrations were decreased. Plasma GH levels showed some fluctuation as a result of the dietary treatments but there was no significant correlation between plasma GH levels and any of the other variables. A significant decrease in plasma thymulin levels was observed in Se-deficient birds compared to those receiving adequate Se in the diet. A vitamin E deficiency had no measurable effect on plasma thymulin levels. From these studies, we conclude that plasma thymulin concentrations directly correlate with plasma T(3) concentrations which are negatively affected by a Se deficiency.
Chang
Wan-Pin
WP
Protein Studies Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
Combs
Gerald F
GF
Scanes
Colin G
CG
Marsh
James A
JA
D000818:Animals; D002645:Chickens / Q000097:blood*; D004032:Diet; D013006:Growth Hormone / Q000378:metabolism; D012643:Selenium / Q000172:deficiency*; D013951:Thymus Hormones / Q000097:blood*; D013963:Thyroid Hormones / Q000097:blood*; D014810:Vitamin E / Q000378:metabolism*
D013951:Thymus Hormones; D013963:Thyroid Hormones; D014810:Vitamin E; D013006:Growth Hormone; D012643:Selenium