GROWTH INDUCED BY DAMAGE
23
grow. But, in fact, they do grow. And they grow at their normal rate,
as evidenced by the color changes in the plucked skin, the time the new
hairs protrude through the surface of the skin, and the time the growing
hair follicles enter the resting phase (Argyris and Trimble, 1964a). The
objection may be raised that plucking such an extensive number of hair
follicles overcomes the inhibitory effects of the tumor. To rule out this
possibility a group of mice have been injected with the Ehrlich ascites
tumor and after the tumor has completely invaded the skin, a small
area of hair follicles adjacent to the tumor has been plucked. The area
plucked is about the size that must be plucked to insure hair growth
normally. It can be seen in Fig. 10 that hair growth occurs in each of
the small plucked areas. It also occurs at the normal rate. Still another
group of mice has been inoculated with the Ehrlich ascites tumor, and
after complete invasion of the overlying skin has occurred, circular or
slit wounds have been made adjacent to the growing tumor. In all cases
hair growth stimulation is seen. Moreover, the time of appearance of
hair growth stimulation is the same as that observed surrounding wounds
made in normal skin (Argyris and Trimble, 1964a). Taken as a whole,
the data strongly suggest that resting hair follicles adjacent to a growing
tumor are fully competent to respond to legitimate cues for growth.
However, in all the cases so far discussed the cues for growth have
been experimentally initiated, either by plucking or wounding. It would
be important to know if resting hair follicles adjacent to a tumor transplant can respond to physiologically initiated cues for growth. To test
this possibility a large number of mice have been inoculated with the
Ehrlich ascites tumor, and the appearance of spontaneous waves of hair
growth has been looked for. When spontaneous waves of hair growth have
been observed, they usually appear first on the sides of the mice and
then travel upward, toward the dorsal skin. They then march right up
to the tumor. Thus resting hair follicles adjacent to tumor transplants
are fully competent to respond to growth stimuli physiologically initiated
(Argyris and Trimble, 1964a).
We conclude that the evidence taken as a whole demonstrates that
resting hair follicles surrounding the tumor implant respond equally well
to experimentally or physiologically initiated cues for growth and, therefore, they are fully competent to grow.
Another major objection to the use of the tumor as a tool for removing
skin mass is the fact that the tumor has replaced that portion of the skin
lost. If the monitoring devices for mass are not organ-specific then, of
course, only mass will be monitored. Since the tumor has replaced the
23
grow. But, in fact, they do grow. And they grow at their normal rate,
as evidenced by the color changes in the plucked skin, the time the new
hairs protrude through the surface of the skin, and the time the growing
hair follicles enter the resting phase (Argyris and Trimble, 1964a). The
objection may be raised that plucking such an extensive number of hair
follicles overcomes the inhibitory effects of the tumor. To rule out this
possibility a group of mice have been injected with the Ehrlich ascites
tumor and after the tumor has completely invaded the skin, a small
area of hair follicles adjacent to the tumor has been plucked. The area
plucked is about the size that must be plucked to insure hair growth
normally. It can be seen in Fig. 10 that hair growth occurs in each of
the small plucked areas. It also occurs at the normal rate. Still another
group of mice has been inoculated with the Ehrlich ascites tumor, and
after complete invasion of the overlying skin has occurred, circular or
slit wounds have been made adjacent to the growing tumor. In all cases
hair growth stimulation is seen. Moreover, the time of appearance of
hair growth stimulation is the same as that observed surrounding wounds
made in normal skin (Argyris and Trimble, 1964a). Taken as a whole,
the data strongly suggest that resting hair follicles adjacent to a growing
tumor are fully competent to respond to legitimate cues for growth.
However, in all the cases so far discussed the cues for growth have
been experimentally initiated, either by plucking or wounding. It would
be important to know if resting hair follicles adjacent to a tumor transplant can respond to physiologically initiated cues for growth. To test
this possibility a large number of mice have been inoculated with the
Ehrlich ascites tumor, and the appearance of spontaneous waves of hair
growth has been looked for. When spontaneous waves of hair growth have
been observed, they usually appear first on the sides of the mice and
then travel upward, toward the dorsal skin. They then march right up
to the tumor. Thus resting hair follicles adjacent to tumor transplants
are fully competent to respond to growth stimuli physiologically initiated
(Argyris and Trimble, 1964a).
We conclude that the evidence taken as a whole demonstrates that
resting hair follicles surrounding the tumor implant respond equally well
to experimentally or physiologically initiated cues for growth and, therefore, they are fully competent to grow.
Another major objection to the use of the tumor as a tool for removing
skin mass is the fact that the tumor has replaced that portion of the skin
lost. If the monitoring devices for mass are not organ-specific then, of
course, only mass will be monitored. Since the tumor has replaced the