Foot Shock Stress Prolongs the Telogen Stage of the Spontaneous Hair Cycle in a Non-Depilated Mouse Model

The study from 16 years ago demonstrated that foot shock stress (FS) in non-depilated mice prolonged the telogen stage of the hair cycle and delayed the onset of the anagen stage over a 3-4 week period. The stressed group of 20 mice showed increased degranulated mast cells, more TUNEL-positive cells indicating apoptosis, and fewer Ki67-positive cells for cell proliferation compared to the control group of 21 mice. Treatment with the substance P NK1 receptor antagonist WIN 62577 in 16 mice partially reversed these effects, suggesting that stress-induced hair cycle changes are mediated by substance P. The study supports the idea that stress-related hair disorders like telogen effluvium and alopecia areata may be influenced by similar mechanisms and that NK1 receptor antagonists could be potential treatments for stress-induced hair loss.