306
L. G A L L I E N
remains to be considered. Definitive progress has been achieved in this
respect in recent years.
1. Production of Steroids by the Gonadal Primordium at Early Stages
of Development
The method consisted of determining, by chromatography and spectrophotometric analysis, the presence of steroids in extracts of embryonic
gonads, in amniotic fluid, in the culture medium, or in the water in which
the organism was raised. When the amount of extract was sufficient, the
biological test of Allen and Doisy for estrogens furnished an additional
check in several cases.
In amphibians, estrone and 17ß-estradiol have been demonstrated from
the ovaries of X. laevis just after metamorphosis and the differentiation
of the gonads (Gallien and Chalumeau-Le Foulgoc, 1960). Dale (1962)
records that, in Rana pipiens, the steroid hormones (corticosteroids, androsterone, 17/3-estradiol) are present in the water in which the animals are
raised, from stage 26 on, which corresponds to the second part of larval
life.
In the chick, estrogens are present in the ovary from the tenth day of
incubation (Gallien and Le Foulgoc, 1957, 1958); Weniger (1965a,b) shows
them from the seventh and eighth days on in the medium from an organ
culture, and Ozon (1965, 1966) demonstrates estrone and 170-estradiol
at the tenth day from the amniotic fluid.
In the guinea pig, Price et al. (1963), using an organ culture of fetal
testes and adrenal glands, shows the presence of androgens at the twentysixth day of gestation. Finally, in the human fetus of 17-21 weeks, Diczfalusy and Troen (1961) have isolated estrone, 17ß-estradiol, and estriol
from various organs and from the amniotic fluid. In this last instance,
however, these steroids are very likely of placental origin.
2. Demonstration of Biosynthetic and Metabolic Enzyme Systems in
Embryos, Larvae, and Fetuses
The authors have attempted to demonstrate the activity of enzyme
systems occurring very early in the metabolism and biosynthesis of steroids.
a. Metabolism. The method used by Ozon (1963), applied to the urodele,
Pleurodeles, consists of administering a pure steroid hormone, 170-estradiol
or 16-ketoestradiol-17ß, to larvae of a specific age. After 24 hours, the
steroids in the water in which the animals are raised is analyzed chromatographically. If new steroids have been created, this indicates that, at the
stage under consideration, the larva possesses enzymatic systems capable of
transforming the original steroid (Table IV).
Breuer el at. (1963) have previously shown in Pleurodeles, by incubation
of the pure hormone in vitro with adult liver, that the liver tissue contained
L. G A L L I E N
remains to be considered. Definitive progress has been achieved in this
respect in recent years.
1. Production of Steroids by the Gonadal Primordium at Early Stages
of Development
The method consisted of determining, by chromatography and spectrophotometric analysis, the presence of steroids in extracts of embryonic
gonads, in amniotic fluid, in the culture medium, or in the water in which
the organism was raised. When the amount of extract was sufficient, the
biological test of Allen and Doisy for estrogens furnished an additional
check in several cases.
In amphibians, estrone and 17ß-estradiol have been demonstrated from
the ovaries of X. laevis just after metamorphosis and the differentiation
of the gonads (Gallien and Chalumeau-Le Foulgoc, 1960). Dale (1962)
records that, in Rana pipiens, the steroid hormones (corticosteroids, androsterone, 17/3-estradiol) are present in the water in which the animals are
raised, from stage 26 on, which corresponds to the second part of larval
life.
In the chick, estrogens are present in the ovary from the tenth day of
incubation (Gallien and Le Foulgoc, 1957, 1958); Weniger (1965a,b) shows
them from the seventh and eighth days on in the medium from an organ
culture, and Ozon (1965, 1966) demonstrates estrone and 170-estradiol
at the tenth day from the amniotic fluid.
In the guinea pig, Price et al. (1963), using an organ culture of fetal
testes and adrenal glands, shows the presence of androgens at the twentysixth day of gestation. Finally, in the human fetus of 17-21 weeks, Diczfalusy and Troen (1961) have isolated estrone, 17ß-estradiol, and estriol
from various organs and from the amniotic fluid. In this last instance,
however, these steroids are very likely of placental origin.
2. Demonstration of Biosynthetic and Metabolic Enzyme Systems in
Embryos, Larvae, and Fetuses
The authors have attempted to demonstrate the activity of enzyme
systems occurring very early in the metabolism and biosynthesis of steroids.
a. Metabolism. The method used by Ozon (1963), applied to the urodele,
Pleurodeles, consists of administering a pure steroid hormone, 170-estradiol
or 16-ketoestradiol-17ß, to larvae of a specific age. After 24 hours, the
steroids in the water in which the animals are raised is analyzed chromatographically. If new steroids have been created, this indicates that, at the
stage under consideration, the larva possesses enzymatic systems capable of
transforming the original steroid (Table IV).
Breuer el at. (1963) have previously shown in Pleurodeles, by incubation
of the pure hormone in vitro with adult liver, that the liver tissue contained