Lesiewicz, 1980  Title: Ornithine decarboxylase in rat skin:
2. Differential response to hair plucking and a tumor promoter.
Authors: Lesiewicz J, Morrison DM, Goldsmith
LA
Journal: J Invest Dermatol 1980 Nov;75(5):411-6
PMID: 7430708, UI: 81048157
Affiliated institution:
Cited in:
Ornithine decarboxylase (OCD; EC 4.1.1.17) activity is induced
in dorsal rat skin by either application of the tumor promoter
12-0-tetradecanoyl-phorbol-13-acetate (TPA) or by hair plucking.
In TPA-treated rat skin, ODC activity does not rise above controls
until 3 hr posttreatment. Following a peak at 4 hr, ODC activity
declines until it reaches control levels at 12 hr. In contrast,
stimulation of skin by hair plucking causes a 50% decrease in
ODC activity by 1 hr. Enzyme activity then increases linearly
to a peak at 4 hr and remains at 3 times control levels up to
12 hr. In skin stimulated by both hair plucking and TPA, and peak
activity is found to exceed the maximum of either stimulus alone
in an additive manner. The response to TPA occurs mainly in the
epidermis, while both the epidermis and dermis show a substantial
response to hair plucking. Both stimuli cause a lengthening of
the half-life of ODC. Stimulation of ODC by hair plucking is insensitive
to indomethacin administration but the TPA-response is inhibited
74%. Stimulation of ODC by hair plucking is inhibited by Actinomycin
D only if Actinomycin D is given at the time of stimulus administration,
and then only partially. The TPA-response is fully inhibited by
Actinomycin D if given at the time of TPA application. Inhibition
is roughly proportional to the duration of Actinomycin D treatment
up to the activity peak at 4 hr. These results indicate that the
tumor promoter, TPA, and the more physiological stimulus, hair
plucking, stimulate skin ornithine decarboxylase activity by different
mechanisms.
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