Date of Award:

1964

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Biochemistry

Abstract

Degenerative disease of old age such as atherosclerosis and cerebral hemorrhage appear to be related to abnormal lipid metabolism. Many investigators have studied the role of steroid hormones on lipid and cholesterol metabolism in rats and chickens. The results have consistantly indicated that both corticosteroids and sex hormones play an important role in the regulation of lipid and cholesterol metabolism, in vivo. Serum cholesterol values in humans have been decreased by estrogens, while androgen administration tends to increase circulating cholesterol. Estrogens have been shown to decrease circulating cholesterol and prevent cholesterol-induced coronary atherosclerosis in chickens. A study of the relationships that exist between concentrations of serum lipids and the concentrations of urinary estrogens and degradation products of androgens and adrenal steroid hormones in normal human subjects should add to our understanding of lipid metabolism in humans.

Observations in rats and chickens limited to meal eating rather than ad libitum feeding, have shown that serum cholesterol was significantly raised in these animals. The rats trained to eat their food in a short period each day also showed markedly increased lipid synthesis. The enhanced lipogenesis resulted in an increase in fat deposition in adipose tissue. These findings have been interpreted to suggest that using frequent small feedings might prove to be beneficial to people who have abnormal lipid metabolism.

Steroids of the adrenal cortex contain cortisol, cortisone, and 17-hydroxy-11-deoxycorticosterone as well as their reduced derivatives. These corticosteroids have a feature which is a two-carbon-alpha-keto side chain at carbon 17. Cortisol which is the predominant product of the human adrenal can be detected by the Porter-Silber Method. This test is specific for a small group of closely related compounds referred to as 17, 21-dihydroxy-20-keto steroids and the 17-hydroxy-11-deoxycorticosterone as well as their derivatives.

The neutral 17-ketosteroids are the catabolic end products of androgens, male hormones, which are produced by testes and adrenal cortex. The 17-keto steroids are excreted in the urine of both normal men and women.

The purpose of the study reported herein was to determine the concentrations of neutral 17-ketosteroids and corticosteroid hormones end products in human urine, as influenced by the number of meals eaten per day. This study was part of a larger problem whose purpose was to determine the relationships that exist between concentrations of serum lipids (cholesterol, total lipids, and lipid phosphorus), and concentrations of estrogens and degradation products of the androgens and adrenal steroid hormones in urine as influenced by dietary factors. The research was based on a group of university students (four men and five women) maintained on self-chosen diets who were eating two meals per day (with breakfast but not lunch) or three meals a day. Urine specimens were collected for hormone estimation and finger-tip blood samples were also given by these subjects for cholesterol determination.

The 17-ketosteroids and corticosteroids in urine were analyzed by chemical methods. The Zimmerman reaction, which involved coupling of the reactive 17-keto group of these compounds with m-dinitrobenzine, was employed in this experiment for analytical purposes. The intensity of color was measured in a Beckman DU spectrophotometer. A modification of the Porter-Silber reaction (Eik-Nes, 1961) was applied to determine the end products of adrenal steroid hormones in urine. This reaction is based on a color reaction between steroids and phenylhydrazine in an acidic condition.

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