16. A C T I O N S OF H O R M O N E S
605
Franke (1946, 1948/49) investigated the direct effect of gonadotrophic
hormones on fragments of ovaries from immature mice kept in natural
medium and also that of the anterior pituitary tissue grown in close
contact with the ovarian explants. He found no difference between
control and experimental cultures.
In contrast, Pavic (1963) demonstrated a direct influence of both
gonadotrophic hormones and anterior pituitary on ovaries from 5-day
rats grown for 6 days in a synthetic medium with 5 or 10% horse
serum. At this stage the ovaries are composed of numerous primordial
follicles: small ova surrounded by two or three layers of follicle cells,
and a few larger follicles in the centre of the ovary. The spaces between
the follicles are occupied by cellular connective tissue.
In control cultures the ova enlarge slightly both in primordial and
larger follicles and some of them display vacuolation of their cytoplasms and degeneration of nuclei. Mitoses are present in follicular and
stromal cells but their number is smaller than in the ovaries in vivo.
In the presence of the ovarian capsule the germinal epithelium is
preserved. It consists of one layer of cuboidal cells among which small
ova can be seen occasionally.
Ovaries grown in contact with anterior pituitary tissue from 23-28day rats show a greater number of large follicles and much increased
proliferation of follicle and stromal cells with abundant cell division
which was three to fourfold that found in the control cultures. On
the other hand, addition of two concentrations (1-8 and 45 /*g/ml)
of a pure follicle-stimulating hormone* to the medium increased the
growth of follicle and stromal cells to a much smaller extent.
Both contact with the pituitary and administration of the higher
dose of follicle-stimulating hormone provoked a greater incidence of
ovular degeneration, but this effect was more pronounced after the
hormone. In contrast, the smaller dose of the hormone did not interfere
with the large ova but stimulated the growth of the germinal epithelium.
The cells were enlarged and more numerous and the development of
young ova was accelerated. Thus, a great number of large spherical
cells, obviously precursors of ova, as well as young ova, could be
distinguished adherent to the inner side of the ovarian capsule.
Gestyl, a gonadotrophin obtained from pregnant mare serum, was
less effective than the pure follicle-stimulating hormone. It did not affect
the growth of follicle cells nor that of the large ova, but in high doses
induced a slight enlargement of the cells of the germinal epithelium.
The difference in effect between gonadotrophic hormones added
to the medium and contact with the anterior pituitary gland is interest*From the National Institutes of Health, Endocrinology Study Section, Bethesda,
Maryland, U.S.A.
605
Franke (1946, 1948/49) investigated the direct effect of gonadotrophic
hormones on fragments of ovaries from immature mice kept in natural
medium and also that of the anterior pituitary tissue grown in close
contact with the ovarian explants. He found no difference between
control and experimental cultures.
In contrast, Pavic (1963) demonstrated a direct influence of both
gonadotrophic hormones and anterior pituitary on ovaries from 5-day
rats grown for 6 days in a synthetic medium with 5 or 10% horse
serum. At this stage the ovaries are composed of numerous primordial
follicles: small ova surrounded by two or three layers of follicle cells,
and a few larger follicles in the centre of the ovary. The spaces between
the follicles are occupied by cellular connective tissue.
In control cultures the ova enlarge slightly both in primordial and
larger follicles and some of them display vacuolation of their cytoplasms and degeneration of nuclei. Mitoses are present in follicular and
stromal cells but their number is smaller than in the ovaries in vivo.
In the presence of the ovarian capsule the germinal epithelium is
preserved. It consists of one layer of cuboidal cells among which small
ova can be seen occasionally.
Ovaries grown in contact with anterior pituitary tissue from 23-28day rats show a greater number of large follicles and much increased
proliferation of follicle and stromal cells with abundant cell division
which was three to fourfold that found in the control cultures. On
the other hand, addition of two concentrations (1-8 and 45 /*g/ml)
of a pure follicle-stimulating hormone* to the medium increased the
growth of follicle and stromal cells to a much smaller extent.
Both contact with the pituitary and administration of the higher
dose of follicle-stimulating hormone provoked a greater incidence of
ovular degeneration, but this effect was more pronounced after the
hormone. In contrast, the smaller dose of the hormone did not interfere
with the large ova but stimulated the growth of the germinal epithelium.
The cells were enlarged and more numerous and the development of
young ova was accelerated. Thus, a great number of large spherical
cells, obviously precursors of ova, as well as young ova, could be
distinguished adherent to the inner side of the ovarian capsule.
Gestyl, a gonadotrophin obtained from pregnant mare serum, was
less effective than the pure follicle-stimulating hormone. It did not affect
the growth of follicle cells nor that of the large ova, but in high doses
induced a slight enlargement of the cells of the germinal epithelium.
The difference in effect between gonadotrophic hormones added
to the medium and contact with the anterior pituitary gland is interest*From the National Institutes of Health, Endocrinology Study Section, Bethesda,
Maryland, U.S.A.