Precursors of Urinary Pregnanediol and Their Influence on the Determination of the Secretory Rate of Progesterone

The metabolic clearance rate of progesterone in males and ovariectomized females.

“…Again the discrepancy in the urinary and plasma production rates is not so great as in the male, but is large enough to warrant caution in using urinary pregnanediol values in the normal female as accurate indexes of circulating progesterone concentrations. This agrees with the conclusions of Arcos and co-workers (22).…”

“…These estimated urinary production rates were determined from the specific activity of pregnanediol in the urine after the injection of radioactive progesterone. However, by using a simultaneous injection of pregnenolone-3H and progesterone-14C, Arcos, Gurpide, Vande Wiele, and Lieberman (22) have reported that progesterone is not the specific and only precursor of 5,8 pregnane, 3a-20a-diol in the male and ovulating females; this confirms that measurement of progesterone production rates (1) from pregnanediol is invalid in the male and suggests that this may also be the case in the female.…”

Metabolic Clearance Rates of Pregnenolone, 17-Acetoxypregnenolone and Their Sulphate Esters in Man and in Rabbit

“…There is good evidence that pregnenolone and its sulphate are secreted by the human adrenal (Wieland, DeCourcy, Levy, Zala & Hirschmann, 1965;Fukushima, Bradlow, Hellman & Gallagher, 1963;Arcos, Gurpide, VandeWiele & Lieberman, 1964;Conrad, Pion & Kitchin, 1967). However, there is no evidence that 17-acetoxypregnenolone and its sulphate are natural products.…”

The Biological Profile of Progesterone 3-Cyclopentyl Enol Ether as Compared with That of Progesterone

“…In fact, if conversion of PCPE to progesterone had occurred in parts of the body other than the intestine, in consideration of the large doses administered, enough progesterone should have been formed to be able to maintain pregnancy. It should also be pointed out that pregnanediol may be derived from steroids other than progesterone (8) and thus its presence in the urine following administration of PCPE does not guarantee that progesterone was an intermediate in its formation.…”