RAPID COMMUNICATION
ZIPGRAM
EPILATION OF GROWING H A I R FOLLICLES ELIZABETH JOHNSON Department o f Zoology, The U n i v e r s i t y , W h i t e k n i g h t s Reading RG6 2AJ, England ABSTRACT E p i l a t e d growing f o l l i c l e s c o n t i n u e t o grow. They produce a l e n g t h o f h a i r which i s s h o r t e r t h a n t h a t produced b y i n t a c t f o l l i c l e s over t h e same p e r i o d o f time, because t h e y grow f o r a s h o r t e r t i m e and a t a lower rate.
When growing h a i r s a r e plucked do t h e f o l l i c l e s c o n t i n u e t o grow? Johnson ( ' 6 5 ) concluded t h a t t h e y do c o n t i n u e t o grow, b u t f o r a s h o r t e r t i m e and more s l o w l y than c o n t r a l a t e r a l unplucked f o l l i c l e s .
On t h e o t h e r
hand Hale and E b l i n g ( ' 7 5 ) suggest t h a t e p i l a t i o n a t any phase o f t h e h a i r c y c l e may a f f e c t t h e t i m e a t which subsequent h a i r s e r u p t b u t does n o t a f f e c t t h e d u r a t i o n o r r a t e o f growth.
It i s d i f f i c u l t t o reconcile t h i s
c o n c l u s i o n w i t h t h e i r statement t h a t p l u c k i n g o f growing h a i r s was never f o l l o w e d by any e r u p t i o n u n t i l t h e appearance o f h a i r s w i t h t a p e r i n g t i p s of t h e subsequent generation.
I f t h i s i s t r u e t h e n one must conclude t h a t
p l u c k i n g o f a growing h a i r stops i t s growth, t h e r e b y s h o r t e n i n g anagen.
If,
on t h e o t h e r hand, fragments o f h a i r were l o s t i n t h e s c a l i n g and s l o u g h i n g o f t h e e p i d e r m i s which f o l l o w e d e p i l a t i o n , i t would be unwise t o comment on t h e growth r a t e .
T h i s r e p o r t p r e s e n t s f u r t h e r evidence on t h i s
problem. MATERIALS AND METHODS Observations were made on n i n e a l b i n o male W i s t a r r a t s f r o m a small randomly mated colony. 259
Growing h a i r s o f Generation
2 (Dry, ' 2 6 ) , t o g e t h e r w i t h t h e i r a d j a c e n t r e s t i n g c l u b h a i r s were plucked from a s t r i p about 2 cm wide a l o n g t h e r i g h t f l a n k , e x t e n d i n g from behind t h e e a r t o t h e h i n d l i m b . control.
The o p p o s i t e f l a n k served as a
Immediately a f t e r e p i l a t i o n each r a t was i n j e c t e d
i n t r a p e r i t o n e a l l y w i t h 1.0 pc DL
- ( 3 5 s ) c y s t i n e h y d r o c h l o r i d e i n 0.9% s a l i n e
(prepared by t h e Radiochemical Centre, Amersham, England) and t h e r e a f t e r a t d a i l y i n t e r v a l s f o r 14 days.
H a i r s were subsequently removed from t h e
e p i l a t e d and c o n t r o l f l a n k s , mounted i n 0.5% g e l a t i n e / 0 . 0 5 % chrome alum on 2" x 2" g l a s s p l a t e s , and exposed f o r 14 days i n c o n t a c t w i t h photographic p l a t e s ( I l f o r d S p e c i a l C o n t r a s t y l a n t e r n p l a t e s ) . Subsequent development o f t h e p h o t o g r a p h i c p l a t e s r e v e a l e d t h e images of t h e r a d i o a c t i v e s p o t s c o r r e s p o n d i n g t o each i n j e c t i o n . RESULTS AND CONCLUSIONS.
When growing h a i r s were p l u c k e d t h e
f o l l i c l e s c o n t i n u e d t o grow t o produce a s h o r t misshapen l e n g t h o f h a i r ( f i g . 1).
The d i s t o r t i o n o f t h e h a i r s h a f t p r o b a b l y r e f l e c t s t h e
p h y s i c a l e f f e c t o f p l u c k i n g , which has p r e v i o u s l y been shown t o break t h e f o l l i c l e a t t h e p o i n t where t h e a c t i v e base narrows i n t o t h e k e r a t i n i z e d h a i r (Johnson and Ebling, ' 6 4 ) .
The l e n g t h o f h a i r produced
a f t e r e p i l a t i o n o f t h e growing f o l l i c l e s was 6 . 5 8
FIGURE LEGEND H a i r s produced f r o m e p i l a t e d growing f o l l i c l e s Marker r e p r e s e n t s 1 mm.
260
0.36 mm.
These
hairs were labelled with (35s) cystine along the whole of their length.
The hairs from the control side were only labelled for that part of their length which was grown after the contralateral side was plucked; during this period 8.89
f
0.45 mm of hair was produced.
The effect of epilation on the growth rate as determined by the distance between the radioactive spots on the autoradiographs has been reported previously (Johnson, '65); the hairs from the epilated follicles grew at a lower rate and for a shorter time than the intact follicles.
The hairs which emerged from the epilated growing follicles are clearly not new hairs but a continuation of growth. This supports the view of David ('34) and Butcher ('59) and confirms the previously reported histological observations on plucked growing follicles (Johnson and
Ebl ing, '64). These results do not necessarily conflict with those of Hale and
Ebling ('75) who report that hair fragments may have been lost in the considerable sloughing and scaling which followed their plucking of growing hairs. In the present investigation sloughing and scaling only followed plucking when the epidermis was accidentally damaged with the forceps, and with care this could be avoided. The present evidence does conflict with the conclusion of these authors that epilation has no effect on duration or rate of hair growth. The hairs that emerged from the plucked growing follicles were shorter because the follicles of the continued t o grow for a shorter time and at a lower rate than intact follicles.
LITERATURE CITED Butcher, E. 0. 1959 Restitutive growth in the hair follicle of the rat. Ann. N.Y. Acad. Sci., 83: 369-477. 262
David, L. 1934 S t u d i e s on t h e e x p r e s s i o n o f g e n e t i c h a i r l e s s n e s s i n t h e house mouse (Mus musculus) J. Exp. Zool., 27: 73-95. Dry, F. W. 1926 The c o a t o f t h e mouse (Mus Musculus) J . Genet., 76: 287-340. Hale, P. A., and E b l i n g , F. J. 1975 The e f f e c t s o f e p i l a t i o n and hormones on t h e a c t i v i t y o f r a t h a i r f o l l i c l e s . J. Exp. ZOO^. , 191 : 49-62. Johnson, E., and E b l i n g , F. J. 1964 The e f f e c t o f p l u c k i n g h a i r s d u r i n g d i f f e r e n t phases o f t h e f o l l i c u l a r c y c l e . J. Embryol. exp. Morph., 12: 465-474. Johnson, E. 1965 I n h e r e n t rhythms o f a c t i v i t y i n t h e h a i r f o l l i c l e and t h e i r c o n t r o l . I n : B i o l o g y o f t h e S k i n and H a i r Growth. A. G. Lyne and B. F. Short, eds. Angus and Robertson,Svdney, pp. 491-505.
263
ZIPGRAM
EPILATION OF GROWING H A I R FOLLICLES ELIZABETH JOHNSON Department o f Zoology, The U n i v e r s i t y , W h i t e k n i g h t s Reading RG6 2AJ, England ABSTRACT E p i l a t e d growing f o l l i c l e s c o n t i n u e t o grow. They produce a l e n g t h o f h a i r which i s s h o r t e r t h a n t h a t produced b y i n t a c t f o l l i c l e s over t h e same p e r i o d o f time, because t h e y grow f o r a s h o r t e r t i m e and a t a lower rate.
When growing h a i r s a r e plucked do t h e f o l l i c l e s c o n t i n u e t o grow? Johnson ( ' 6 5 ) concluded t h a t t h e y do c o n t i n u e t o grow, b u t f o r a s h o r t e r t i m e and more s l o w l y than c o n t r a l a t e r a l unplucked f o l l i c l e s .
On t h e o t h e r
hand Hale and E b l i n g ( ' 7 5 ) suggest t h a t e p i l a t i o n a t any phase o f t h e h a i r c y c l e may a f f e c t t h e t i m e a t which subsequent h a i r s e r u p t b u t does n o t a f f e c t t h e d u r a t i o n o r r a t e o f growth.
It i s d i f f i c u l t t o reconcile t h i s
c o n c l u s i o n w i t h t h e i r statement t h a t p l u c k i n g o f growing h a i r s was never f o l l o w e d by any e r u p t i o n u n t i l t h e appearance o f h a i r s w i t h t a p e r i n g t i p s of t h e subsequent generation.
I f t h i s i s t r u e t h e n one must conclude t h a t
p l u c k i n g o f a growing h a i r stops i t s growth, t h e r e b y s h o r t e n i n g anagen.
If,
on t h e o t h e r hand, fragments o f h a i r were l o s t i n t h e s c a l i n g and s l o u g h i n g o f t h e e p i d e r m i s which f o l l o w e d e p i l a t i o n , i t would be unwise t o comment on t h e growth r a t e .
T h i s r e p o r t p r e s e n t s f u r t h e r evidence on t h i s
problem. MATERIALS AND METHODS Observations were made on n i n e a l b i n o male W i s t a r r a t s f r o m a small randomly mated colony. 259
Growing h a i r s o f Generation
2 (Dry, ' 2 6 ) , t o g e t h e r w i t h t h e i r a d j a c e n t r e s t i n g c l u b h a i r s were plucked from a s t r i p about 2 cm wide a l o n g t h e r i g h t f l a n k , e x t e n d i n g from behind t h e e a r t o t h e h i n d l i m b . control.
The o p p o s i t e f l a n k served as a
Immediately a f t e r e p i l a t i o n each r a t was i n j e c t e d
i n t r a p e r i t o n e a l l y w i t h 1.0 pc DL
- ( 3 5 s ) c y s t i n e h y d r o c h l o r i d e i n 0.9% s a l i n e
(prepared by t h e Radiochemical Centre, Amersham, England) and t h e r e a f t e r a t d a i l y i n t e r v a l s f o r 14 days.
H a i r s were subsequently removed from t h e
e p i l a t e d and c o n t r o l f l a n k s , mounted i n 0.5% g e l a t i n e / 0 . 0 5 % chrome alum on 2" x 2" g l a s s p l a t e s , and exposed f o r 14 days i n c o n t a c t w i t h photographic p l a t e s ( I l f o r d S p e c i a l C o n t r a s t y l a n t e r n p l a t e s ) . Subsequent development o f t h e p h o t o g r a p h i c p l a t e s r e v e a l e d t h e images of t h e r a d i o a c t i v e s p o t s c o r r e s p o n d i n g t o each i n j e c t i o n . RESULTS AND CONCLUSIONS.
When growing h a i r s were p l u c k e d t h e
f o l l i c l e s c o n t i n u e d t o grow t o produce a s h o r t misshapen l e n g t h o f h a i r ( f i g . 1).
The d i s t o r t i o n o f t h e h a i r s h a f t p r o b a b l y r e f l e c t s t h e
p h y s i c a l e f f e c t o f p l u c k i n g , which has p r e v i o u s l y been shown t o break t h e f o l l i c l e a t t h e p o i n t where t h e a c t i v e base narrows i n t o t h e k e r a t i n i z e d h a i r (Johnson and Ebling, ' 6 4 ) .
The l e n g t h o f h a i r produced
a f t e r e p i l a t i o n o f t h e growing f o l l i c l e s was 6 . 5 8
FIGURE LEGEND H a i r s produced f r o m e p i l a t e d growing f o l l i c l e s Marker r e p r e s e n t s 1 mm.
260
0.36 mm.
These
hairs were labelled with (35s) cystine along the whole of their length.
The hairs from the control side were only labelled for that part of their length which was grown after the contralateral side was plucked; during this period 8.89
f
0.45 mm of hair was produced.
The effect of epilation on the growth rate as determined by the distance between the radioactive spots on the autoradiographs has been reported previously (Johnson, '65); the hairs from the epilated follicles grew at a lower rate and for a shorter time than the intact follicles.
The hairs which emerged from the epilated growing follicles are clearly not new hairs but a continuation of growth. This supports the view of David ('34) and Butcher ('59) and confirms the previously reported histological observations on plucked growing follicles (Johnson and
Ebl ing, '64). These results do not necessarily conflict with those of Hale and
Ebling ('75) who report that hair fragments may have been lost in the considerable sloughing and scaling which followed their plucking of growing hairs. In the present investigation sloughing and scaling only followed plucking when the epidermis was accidentally damaged with the forceps, and with care this could be avoided. The present evidence does conflict with the conclusion of these authors that epilation has no effect on duration or rate of hair growth. The hairs that emerged from the plucked growing follicles were shorter because the follicles of the continued t o grow for a shorter time and at a lower rate than intact follicles.
LITERATURE CITED Butcher, E. 0. 1959 Restitutive growth in the hair follicle of the rat. Ann. N.Y. Acad. Sci., 83: 369-477. 262
David, L. 1934 S t u d i e s on t h e e x p r e s s i o n o f g e n e t i c h a i r l e s s n e s s i n t h e house mouse (Mus musculus) J. Exp. Zool., 27: 73-95. Dry, F. W. 1926 The c o a t o f t h e mouse (Mus Musculus) J . Genet., 76: 287-340. Hale, P. A., and E b l i n g , F. J. 1975 The e f f e c t s o f e p i l a t i o n and hormones on t h e a c t i v i t y o f r a t h a i r f o l l i c l e s . J. Exp. ZOO^. , 191 : 49-62. Johnson, E., and E b l i n g , F. J. 1964 The e f f e c t o f p l u c k i n g h a i r s d u r i n g d i f f e r e n t phases o f t h e f o l l i c u l a r c y c l e . J. Embryol. exp. Morph., 12: 465-474. Johnson, E. 1965 I n h e r e n t rhythms o f a c t i v i t y i n t h e h a i r f o l l i c l e and t h e i r c o n t r o l . I n : B i o l o g y o f t h e S k i n and H a i r Growth. A. G. Lyne and B. F. Short, eds. Angus and Robertson,Svdney, pp. 491-505.
263
