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Parotid fluid corticosteroids, substantially comprised of cortisol and cortisone, were previously demonstrated to rise to far greater levels 4 hr after administration of ACTH than they did in the third trimester of pregnancy, although the plasma total corticosteroid concentrations were similar in these two states. It was therefore suggested that only nonproteinbound corticosteroid gains access to parotid fluid. In the present study parotid fluid cortisol and cortisone and plasma dialyzable cortisol concentrations have been measured in normal men before and 2 hr after 40 U ACTH, and, in another group, before and after 10 days of diethystilbestrol (5 mg daily). Total plasma cortisol rose from a mean of 6.3 to 17.9 mug/100 ml after ACTH and from 14.6 to 39.4 mg/100 ml after the estrogen. However parotid fluid cortisol plus cortisone rose from 0.8 to 2.6 mug/100 ml after ACTH and to only 2.2 after estrogen. This rise resembled that of the plasma dialyzable cortisol (control 0.4, ACTH 1.8, estrogen 1.2 mug/100 ml) rather than the increase in total plasma cortisol which was over twice as high after estrogen as after ACTH. Thus parotid fluid corticosteroids seem to be a good measure of nonprotein-bound corticosteroid, the cortisol available to the cell. The total amount of cortisol plus cortisone excreted is approximately constant, independent of parotid fluid flow rate. Cortisone exceeds cortisol in parotid fluid in the basal state, but after ACTH the situation is reversed.

The effects of estriol and estradiol on the plasma levels of cortisol- and thyroxine-binding globulin activity, and on the secretion rates of aldosterone and cortisol were studied in man. The metabolite estriol had no consistent or significant influence on plasma levels of the hormone-binding globulin activities; the hormone estradiol increased these binding capacities significantly, as expected. Cortisol secretion rate rose slightly after estriol but was unchanged after estradiol. Both compounds induced substantial increases in the aldosterone secretion rate of most treated subjects. The mechanism of this apparently paradoxical effect of estrogens is not clear; it is suggested that the "salt-retaining" action of estrogens is mediated in part by the rapid enhancement of aldosterone output which follows their administration in man. Balance experiments in four subjects suggest that both estradiol and estriol may induce a transient early natriuresis in man; but other mechanisms for estrogen stimulation of aldosterone secretion may be operative as well.