Date of Award:

1966

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Biochemistry

Abstract

In the last few years, much research has been done on lipid metabolism because of the possible involvement of lipids in atherosclerosis and coronary heart disease. These diseases appear to be related to abnormalities in lipid metabolism. Since sex differences have been noted in lipid metabolism, the role of steroid hormones has been under investigation in a number of laboratories. Coronary heart disease occurs only rarely in women during the reproductive phase. In men, the administration of estrogens results in a decreased serum cholesterol level while androgens tend to increase circulating cholesterol.

Experiments on rats and chickens have indicated that both corticosteroids and sex hormones are involved in the regulation of lipid and cholesterol metabolism. In chickens, estrogens decreased the circulating cholesterol and prevented the coronary atherosclerosis that can be induced by feeding cholesterol. The effect of estrogens and androgens on the metabolism of essential fatty acids in rats is under investigation by Ostwald et al. (1965). Female or estrogen-treated rats maintained more arachidonic acid in their plasma phospholipids and cholesteryl esters than did their male counterparts even during acute and prolonged deficiencies of dietary linoleic acid.

Adrenal cortex contains a number of potent hormones all of which are steroid derivatives having characteristic cyclopentanoperhydrophenanthrene nucleus. The corticosteroids are produced by the adrenal gland in both male and female. One measure of corticosteroids activity is the determination of urinary 17, 21-dihydroxy-20-ketosteroids.

The androgens in female are produced by the adrenal cortex and in small amounts by the ovary; in the male by the testis and to a lesser extent in the adrenal cortex. Measurement of the urinary neutral 17-ketosteroids is becoming more frequently used as an index of androgenic activity but it should be borne in mind that the androgenic ptency of a given urine extract will not necessarily parallel 17-ketosteroid concentration.

Until more is known about androgen and 17,21-dihydroxy-20-ketosteroids (DKS), male adrenals, as well as possible androgen secretion by the ovary, the significance of normal neutral 17-ketosteroids and 17,21-dihydroxy-20-ketosteroids determinations in urine are of considerable importance when measured regularly for long periods of time. The measurement of the output of these steroids during several menstrual periods would provide a biochemical index of androgen and corticosteroids secretion in women.

Few, detailed studies of changes in urinary excretion of androgen and corticosteroid end products during the menstrual cycle in normal young women have been reported in the literature. Yu (1964) found that neutral 17-ketosteroids gradually increased from the 9 to 15 days. This increase was significant. However, she did not have values for the rest of menstrual period on her five subjects. Her results indicated that a more detailed study of changes occurring during the menstrual cycle was desirable. Then, if these changes were related to concentrations of the serum fatty acids during the menstrual cycle, basic information on relationships between steroid hormones and lipid metabolism might be obtained. The findings should be important because abnormal metabolism of lipids seems to be one factor involved in several of the degenerative diseases of old age such as atherosclerosis and cerebral hemorrhage.

This study is a part of a larger problem to determine relationships that exist among serum cholesterol, serum fatty acids, and concentrations of estrogens and degradations products of the androgens and corticosteroids in urine in normal young women. The purpose of this study is to determine the changes in concentrations of neutral 17-ketosteroid and 17,21-dihydoxy-20-ketosteroid hormones in women's urine during specified days of the menstrual period, which would help to define the effect of ovulation on the urinary excretion of these hormones.

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