16. A C T I O N S OF H O R M O N E S
625
described by Lasnitzki (1955a), and, unlike her, found an increase of
stroma and muscle in treated glands of all ages.
2. Effects of 0estrogens
(a) Effect on the rodent vagina. In most sexually mature rodents the
vaginal epithelium undergoes cyclic changes under the influence of
endogenous oestrogen and progesterone. During dioestrus or before
puberty the epithelium consists of a row of cuboidal cells beneath an
outer layer of mucined cells. During oestrus, or after injection or local
application of oestrogens, the basal cells multiply and differentiate into
squamous keratinizing epithelium and the superficial mucified cells
are shed.
Vaginal explants from immature rats and mice have, with one exception been found to form such stratified keratinizing epithelium shortly
after explantation into normal medium, but addition of oestrogen to
the medium usually hastens and increases the squamous changes.
Dux (1941) was the first to demonstrate this direct effect of the hormone
in vaginal explants from young rats grown either in medium to which
oestrogen had been added or in serum from animals injected with the
hormone. Untreated cultures developed squamous keratinizing epithelium, including a layer of cells containing keratohyalin beneath the
keratin. In explants treated with oestrogen there was a marked increase in the number and size of the keratohyalin granules accompanied
by precocious but incomplete keratinization.
Kahn (1954) found that the addition of oestrone to the medium of
vaginal explants from immature rats (1-3 /zg/ml) considerably hastened
the stratification and cornification of the epithelium. Explants grown
with oestrone formed squamous cornifying epithelium within 2 days
growth, whereas the control cultures underwent the same process
between the fourth and fifth day. Lasnitzki (1961a) reported that
spontaneous and oestrone-induced squamous changes occurred almost
simultaneously in mouse vaginae from mice 2-3 weeks old, but in the
hormone-treated explants (2 /xg/ml) the cell number and the amount
of keratin was increased, resulting in a thicker epithelium (Figs. 17, 18).
These changes were not dependent on the type of medium used, as they
were seen in both biological and protein-free denned medium (Lasnitzki,
1961b). The acceleration and increase of the squamous differentiation
by the hormone, however, seemed to depend on its concentration, since
Martin (1959) who used considerably smaller doses of oestrone
(0-05 /xg/culture) failed to notice any difference between oestronetreated and control cultures of mouse vagina.
Biggers, Claringbold and Hardy (1956) who studied the effect of 11
different oestrogens on the vaginal epithelium of very young mice,
625
described by Lasnitzki (1955a), and, unlike her, found an increase of
stroma and muscle in treated glands of all ages.
2. Effects of 0estrogens
(a) Effect on the rodent vagina. In most sexually mature rodents the
vaginal epithelium undergoes cyclic changes under the influence of
endogenous oestrogen and progesterone. During dioestrus or before
puberty the epithelium consists of a row of cuboidal cells beneath an
outer layer of mucined cells. During oestrus, or after injection or local
application of oestrogens, the basal cells multiply and differentiate into
squamous keratinizing epithelium and the superficial mucified cells
are shed.
Vaginal explants from immature rats and mice have, with one exception been found to form such stratified keratinizing epithelium shortly
after explantation into normal medium, but addition of oestrogen to
the medium usually hastens and increases the squamous changes.
Dux (1941) was the first to demonstrate this direct effect of the hormone
in vaginal explants from young rats grown either in medium to which
oestrogen had been added or in serum from animals injected with the
hormone. Untreated cultures developed squamous keratinizing epithelium, including a layer of cells containing keratohyalin beneath the
keratin. In explants treated with oestrogen there was a marked increase in the number and size of the keratohyalin granules accompanied
by precocious but incomplete keratinization.
Kahn (1954) found that the addition of oestrone to the medium of
vaginal explants from immature rats (1-3 /zg/ml) considerably hastened
the stratification and cornification of the epithelium. Explants grown
with oestrone formed squamous cornifying epithelium within 2 days
growth, whereas the control cultures underwent the same process
between the fourth and fifth day. Lasnitzki (1961a) reported that
spontaneous and oestrone-induced squamous changes occurred almost
simultaneously in mouse vaginae from mice 2-3 weeks old, but in the
hormone-treated explants (2 /xg/ml) the cell number and the amount
of keratin was increased, resulting in a thicker epithelium (Figs. 17, 18).
These changes were not dependent on the type of medium used, as they
were seen in both biological and protein-free denned medium (Lasnitzki,
1961b). The acceleration and increase of the squamous differentiation
by the hormone, however, seemed to depend on its concentration, since
Martin (1959) who used considerably smaller doses of oestrone
(0-05 /xg/culture) failed to notice any difference between oestronetreated and control cultures of mouse vagina.
Biggers, Claringbold and Hardy (1956) who studied the effect of 11
different oestrogens on the vaginal epithelium of very young mice,