Effect of parathyroid hormone on mice hair cycle and growth

To investigate the effect of PTH(7～34) or PTH(1～34) on C57BL6 mice hair cycle and hair growth in vibrissa follicles culture in vitro. Normal C57BL6 mice with hair in telogen as animal model, anagen was induced by depilation of hair shafts with wax/resin mixture, simultaneously PTH(7～34) was given intraperitoneally for 19 days, observed the hair cycle changes daily. The results showed that after depilation the skin of giving PTH(7～34) mice progressed to anagen on day 5, about 24 hours earlier than control group; on day 19, most hair of the control group progressed to catagen or telogen, but there were large areas of skin of the PTH(7～34) group maintained in anagen. In hair follicle culture, giving 10-6mol/L or 10-7mol/L PTH(7～34) , the hair shaft growth was significantly faster than control group (P 0.01), but the 10-9mol/L PTH(1～34) group was slower than control (P 0.01). These suggested that PTH(7～34) might prolong anagen, increase hair growth, but PTH(1～34) showed suppression effect on hair growth.