The development of an assay method for ACTH
based on its inhibiting effect on the formation of granulation tissue, and examination
of the physiological factors affecting the
response of experimental wound healing to
Adrenal function in guinea pigs with particular reference to scurvy.
1). Adrenocorticotrophic hormone inhibits the formation
of granulation tissue in mice, and this fact has been used as the basis of an assay in which a quantal response is measured.
Potencies by this method and that of Sayers, Sayers and
Woodbury (1948) are in close agreement.
2). Physiological factors affecting the response of
experimental wound healing to ACTH have been investigated in
a). No gonadotrophic activity was detected in the
sample of ACTH used, and pitressin tannate and
chorionic gonadotrophin did not produce this effect.
b). Hypophysectomised mice became progressively and
rapidly less responsive to ACTH.
c). The gonads were essential for inhibition in very
young and in mature mice.
d). Adrenalectomised mice at the beginning of the
breeding season, adrenalectomised pregnant mice,
and adrenalectomised mice pretreated with chorionic
gonadotrophin showed inhibition of healing by ACTH.
Adrenalectomised mice pretreated with follicle - stimulating hormone or pregnant mares' serum gonadotrophin_ were not inhibited.
e). Cortisone acetate caused inhibition in intact and
gonadectomised mice. Neither testosterone, oestriol
nor oestradiol had any effect, but progesterone
gave definite impairment under the conditions of
f). It is suggested that in mice the gonads are
capable of responding to ACTH under the influence
of luteinizing hormone.
3). Cortisone does not inhibit healing in guinea pigs.
4) . a)Guinea pigs placed on a scorbutic diet showed a gradual increase of varying extent in urinary
17- ketosteroid excretion. This reached a peak
in the terminal phases. No increase occurred in
the absence of the adrenals, but the increase was unaffected by castration.
b). Daily administration of ACTH in acute scurvy failed
to influence the fall in body weight or time of
c). Daily administration of cortisone failed to influence the ultimate outcome of acute anC chronic
scurvy. Cortisone prevented adrenal hypertrophy
in scurvy, and in chronic (but not acute) scurvy
it reduced the haemorrhagic manifestations.
d). In animals maintained on a dose of ascorbic acid
leading to chronic scurvy, cortisone stimulated
new bone formation at the epiphyses.
5). In the late stages of acute scurvy when adrenal
ascorbic acid is minimal, there is still a normal response
to exogenous ACTH as judged by a rise in urinary 17 -ketosteroid excretion, over and above that due to developing
6). Normal pregnant guinea pigs show a greater response
to ACTH than non - pregnant ones. Urinary 17- ketosteroid
excretion was not increased by gonadotrophin administration to
7). It has been shown that dehydroascorbic acid (DHA)
is antiscorbutic. DHA administration leads to the development
of characteristic features, which include fatty degeneration
of the liver, flexion of the fore and hind feet and partial
hind -leg paresis.
8). The dietary intake of adrenalectomised animals has
been measured. The possible presence of an important dietary
factor, other than ascorbic acid, in cabbage has been