Doctoral Dissertations

Date of Award

12-1992

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Animal Science

Major Professor

J.P. Hitchcock

Committee Members

Sharon Melton, Jim Miller, Roy Beauchene, Henry Kattesh

Abstract

Four experiments were conducted to assess the physiological effects of alpha-tocopherol, ascorbic acid, and iron on lipid peroxidation, tissue iron distribution, blood platelet aggregation and concentration, polymorphonuclear leukocyte concentration, hematological and performance parameters utilizing rats and pigs. The primary emphasis was placed on alpha-tocopherol and its interactive effects with ascorbic acid and iron.

In the first experiment 96 male Sprague-Dawley rats weighing between 51 and 75 grams were utilized in a 4 x 2 factorial arrangement with six animals per treatment. The treatments consisted of four added dietary levels of alpha-tocopheryl acetate: 7.5, 25, 37.5, and 75 lU/kg and two dietary concentrations of ascorbic acid: 0 and 0.5%.

The second experiment utilized 48 Sprague-Dawley rats weighing between 17 5 and 2 00 grams in a 2 x 2 factorial arrangement with eight animals per treatment. The treatments consisted of two added dietary levels of alpha-tocopheryl acetate: 30 and 300 lU/kg and two dietary levels of ascorbic acid: 0 and 0.5%. The third study utilized 48 three-day-old Yorkshire x Duroc x Hampshire pigs in a 3 x 2 factorial arrangement with eight pigs per treatment. The treatments consisted of 3 levels of iron injection: 0, 100, or 400 mg and two levels of alpha tocopherol injection: 0 or 900 lU. The fourth experiment utilized 48 weaned Yorkshire x Duroc x Hampshire pigs from 6 litters in a 4 x 2 factorial arrangement with four dietary additions of alpha-tocopheryl acetate: 0, 100, 300, and 1000 lU/kg and two dietary levels of ascorbic acid: 0 and 0.2%.

The results obtained indicated that added dietary concentrations of alpha-tocopheryl acetate significantly decreased lipid peroxidation in the tissues of rats and pigs regardless of the age and size of the animal involved. Injection of alpha-tocopherol also significantly decreased lipid peroxidation in the tissues of baby pigs. The decrease in lipid peroxidation appeared to be linear with lipid peroxidation decreasing inversely as biological concentrations of alpha-tocopherol increased.

The results from experiment two provided evidence that dietary supplementation with alpha-tocopheryl acetate at 3000 lU/kg significantly decreased blood platelet aggregation on day 21 and 28 of the experiment in 200 and 250 gram rats. Blood platelet concentration was not affected by dietary alpha-tocopheryl acetate or ascorbic acid.

Experiment two appeared to indicate that added dietary additions of alpha-tocopheryl acetate significantly increased the percentage of polymorphonuclear leukocytes (PMN) in white blood cells during the last week of the trial. Ascorbic acid did not appear to significantly increase PMN concentrations in white blood cells.

The results obtained from these experiments indicated that added dietary concentrations of alpha-tocopheryl acetate significantly increased plasma iron concentration, decreased total iron binding capacity in plasma and decreased tissue concentrations of iron.

Injected iron at 400 mg significantly increased lipid peroxidation in the plasma and tissues of baby and weaned pigs.

Added dietary levels of ascorbic acid did not appear to physiologically interact with pharmacological concentrations of alpha-tocopherol based on the variables measured except for the reduction of lipid peroxidation in plasma and the tissues analyzed.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS