3. LIPIDS: STEROID METABOLISM
181
Testosterone has been found in the spermatic vein blood of man
(81) and the dog (82), and progesterone in the ovarian vein blood of
the ewe (83) and the goat (84). Progesterone and the androgen dehydroepiandrosterone have been found in adrenal venous blood in man
and the ox (56, 59, 60). Otherwise evidence for the elaboration of
steroid sex hormones by these tissues is indirect. In no case has the
presence of an estrogenic steroid been demonstrated in the blood draining from an endocrine gland.
b. Biosynthesis of Estrogenic Steroids. The principal known estrogenic steroids excreted by man are estrone (XXVI), estradiol-17/3
(XXVII), and estriol (XXIX). The recently isolated 16o:-hydroxyestrone
(XXVIII) (85) may be a urinary estrogenic steroid of considerable
quantitative importance. A variety of other estrogenic steroids have
also been found in minor amounts in the urine of pregnant women
(86).
Progesterone
► 17a-Hydroxyprogesterone
► Androstenedione
Estradiol-170
(XXVII)
Estrone
(XXVI)
19-Hydroxyandrostenedione
(XXV)
Estriol
(XXIX)
16a -Hydroxy estrone
(XXVIII)
FIG. 4. Scheme for the biosynthesis of estrogenic steroids.
Estriol is usually regarded as being formed exclusively in man, but
it has recently been reported in the urine of a dog given estradiol-17/2
(87), among the products of incubating rat liver with estrone (88), in
the blood of a rat infused with C
14 -estrone (89), and in the ovaries of
laying hens (90). In no case, however, has crystalline estriol been isolated and thoroughly characterized.
181
Testosterone has been found in the spermatic vein blood of man
(81) and the dog (82), and progesterone in the ovarian vein blood of
the ewe (83) and the goat (84). Progesterone and the androgen dehydroepiandrosterone have been found in adrenal venous blood in man
and the ox (56, 59, 60). Otherwise evidence for the elaboration of
steroid sex hormones by these tissues is indirect. In no case has the
presence of an estrogenic steroid been demonstrated in the blood draining from an endocrine gland.
b. Biosynthesis of Estrogenic Steroids. The principal known estrogenic steroids excreted by man are estrone (XXVI), estradiol-17/3
(XXVII), and estriol (XXIX). The recently isolated 16o:-hydroxyestrone
(XXVIII) (85) may be a urinary estrogenic steroid of considerable
quantitative importance. A variety of other estrogenic steroids have
also been found in minor amounts in the urine of pregnant women
(86).
Progesterone
► 17a-Hydroxyprogesterone
► Androstenedione
Estradiol-170
(XXVII)
Estrone
(XXVI)
19-Hydroxyandrostenedione
(XXV)
Estriol
(XXIX)
16a -Hydroxy estrone
(XXVIII)
FIG. 4. Scheme for the biosynthesis of estrogenic steroids.
Estriol is usually regarded as being formed exclusively in man, but
it has recently been reported in the urine of a dog given estradiol-17/2
(87), among the products of incubating rat liver with estrone (88), in
the blood of a rat infused with C
14 -estrone (89), and in the ovaries of
laying hens (90). In no case, however, has crystalline estriol been isolated and thoroughly characterized.