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Hair News - October 2003 |
| Author: Karen Shelton |
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Date: October 2003 |
Topical Minoxidil Counteracts Stress-induced
Hair Growth Inhibition In Mice
Arck PC, Handjiski B, Peters EM, Hagen
E, Klapp BF, Paus R
Department of Internal Medicine, Charite, Humboldt University,
Berlin, Germany.
petra.arck@charite.de
Stress has long been suspected as a possible cause of hair loss in
various species, even though convincing experimental evidence has not
been available. Recently, we have shown in a murine model that sonic
stress alters hair growth and cycling in vivo, and have postulated the
existence of a 'brain-hair follicle axis' (BHA).
In order to study whether a clinically available and widely used
topically active hair growth stimulator mitigates stress-triggered hair
growth inhibition in this stress model, we have applied a 5% minoxidil
solution.
Female CBA/J mice were depilated and randomized in to two groups:
control (n = 20) and sonic stress (n = 20). These groups were further
divided and either treated daily with 5% minoxidil solution or vehicle
alone.
The stress group was exposed to sonic stress for 24 h starting 14
days after anagen induction by depilation. All mice were sacrificed 16
days after the depilation and assessed by quantitative histomorphometry.
Sonic stress significantly increased the number of hair follicles
with apoptotic cells and inhibited intrafollicular keratinocyte
proliferation. In addition, the number of clusters of perifollicular MHC
class II+ cells and degranulated perifollicular mast cells was
significantly enhanced in the stressed mice. In accordance with previous
findings, all stressed mice showed an advanced hair cycle progression
towards catagen.
All of these stress-induced hair growth inhibitory changes along the
BHA were down-regulated by topical minoxidil application.
This encourages one to explore clinically whether topical minoxidil
is a safe and effective pharmacologic tool for the management of
stress-associated telogen effluvium in humans |