638
ILSE LASNITZKI
insulin-treated explants alveoli reformed from the collapsed state into
round slightly dilated elements but the lining epithelium was lower
and the cells fewer in number than those seen in the prelactating gland.
The same effect was obtained in explants kept with insulin and Cortisol.
A combination of these two hormones with either mammotrophin or
somatotrophin or with both pituitary hormones induced secretory
activity in these non-lactating glands. In such cultures, the cytoplasm
of the alveolar cells became vacuolated and secretory matter was
released into the lumen, but the amount was less than that observed
in the prelactating organ.
The stimulation of secretory function may be bound up with the
influence of the pituitary hormones on carbohydrate metabolism. As
shown by Weinberg, Habbard, Williams and Field (1961) prolactin
and growth hormone increase glucose uptake and oxidation in mammary glands from pregnant and nursing rats in vivo; the stimulation rose
to a maximum during late lactation and disappeared after weaning.
It is interesting that the response to some of the hormones studied
varies with the age and functional stage of the organ. Progesterone
inhibits the growth of the embryonic organ but promotes it in the
young virgin gland. Mammotrophin or prolactin stimulates the growth
of the epithelium in the embryonic and virgin gland but acts as a lactogenic hormone in the prelactating and post-lactating organ. Finally,
the corticosteroids which in the embryonic and virgin glands produce
effects suggestive of the first steps of secretory activity help to maintain
the structure in the mature organ.
The findings that either mammotrophin or somatotrophin with
insulin and Cortisol stimulate secretion correspond with in vivo results
by Nandi (1958b) who found that the two hormones could be interchanged and that either provoked secretory activity in glands of the
same stage.
A. COMPARISON OF HORMONE DEPENDENCE BETWEEN
NORMAL MAMMARY TISSUE, HYPERPLASTIC NODULES AND
MAMMARY TUMOURS
It is known that tumours derived from hormone-controlled tissues
may remain hormone-dependent for a time and that their growth can
be checked temporarily by withdrawal of the hormones they require
or by administration of their antagonists. The question of whether
or not a tumour is still hormone-dependent is therefore not only of
theoretical but also of immense practical value. Elias and Rivera
(1959) compared the sensitivity to hormones of non-lactating and prelactating glands with that of hyperplastic nodules which are considered
ILSE LASNITZKI
insulin-treated explants alveoli reformed from the collapsed state into
round slightly dilated elements but the lining epithelium was lower
and the cells fewer in number than those seen in the prelactating gland.
The same effect was obtained in explants kept with insulin and Cortisol.
A combination of these two hormones with either mammotrophin or
somatotrophin or with both pituitary hormones induced secretory
activity in these non-lactating glands. In such cultures, the cytoplasm
of the alveolar cells became vacuolated and secretory matter was
released into the lumen, but the amount was less than that observed
in the prelactating organ.
The stimulation of secretory function may be bound up with the
influence of the pituitary hormones on carbohydrate metabolism. As
shown by Weinberg, Habbard, Williams and Field (1961) prolactin
and growth hormone increase glucose uptake and oxidation in mammary glands from pregnant and nursing rats in vivo; the stimulation rose
to a maximum during late lactation and disappeared after weaning.
It is interesting that the response to some of the hormones studied
varies with the age and functional stage of the organ. Progesterone
inhibits the growth of the embryonic organ but promotes it in the
young virgin gland. Mammotrophin or prolactin stimulates the growth
of the epithelium in the embryonic and virgin gland but acts as a lactogenic hormone in the prelactating and post-lactating organ. Finally,
the corticosteroids which in the embryonic and virgin glands produce
effects suggestive of the first steps of secretory activity help to maintain
the structure in the mature organ.
The findings that either mammotrophin or somatotrophin with
insulin and Cortisol stimulate secretion correspond with in vivo results
by Nandi (1958b) who found that the two hormones could be interchanged and that either provoked secretory activity in glands of the
same stage.
A. COMPARISON OF HORMONE DEPENDENCE BETWEEN
NORMAL MAMMARY TISSUE, HYPERPLASTIC NODULES AND
MAMMARY TUMOURS
It is known that tumours derived from hormone-controlled tissues
may remain hormone-dependent for a time and that their growth can
be checked temporarily by withdrawal of the hormones they require
or by administration of their antagonists. The question of whether
or not a tumour is still hormone-dependent is therefore not only of
theoretical but also of immense practical value. Elias and Rivera
(1959) compared the sensitivity to hormones of non-lactating and prelactating glands with that of hyperplastic nodules which are considered