076 Cultured Human Dermal Papilla Cells Secrete Adrenomedullin: Effect of Testosterone, 17beta Estradiol and Phenol Red

MJ Thornton, A J Reed, 1AG Messenger, 2R Pio & 2A Martinez. Dept Biomedical Sciences, University of Bradford, UK, 1Royal Hallamshire Hospital, Sheffield, UK 2Dept Cell and Cancer Biology, NIH, Bethesda, USA

Adrenomedullin (AM) is a recently discovered pluripotent peptide, which can act as a mitogen, an angiogenic factor and an apoptosis survival factor. Therefore we have investigated the production of AM by cultured human dermal papilla cells derived from beard and scalp hair follicles. Cells were cultured in 25cm2 flasks in DMEM and 10% FBS until sub-confluent. The media was removed, cells washed twice with PBS and incubated with either serum-free DMEM +/- 10nM testosterone or serum-free, phenol red-free DMEM +/- 10nM 17beta-estradiol. Conditioned medium was collected after 15min and 24h, and the concentrations of AM determined by RIA. All cells (n=6) secreted AM. The concentration of AM after 24h was 10x that detected after 15min. Scalp cells appeared to secrete slightly more AM than beard cells at both time points. However, there was a big difference in the amount of AM produced by cells incubated in the presence of phenol red. Cells incubated in medium containing phenol red secreted 1.5-2x the level of AM after 24h compared to those incubated in phenol red-free medium. There was no effect on AM secretion by cells incubated with 17beta estradiol on either cell type. There was no effect on AM secretion by scalp cells incubated with testosterone, however, the production of AM by beard cells incubated with testosterone after 24h was almost double that of corresponding beard cells incubated in the absence of testosterone. Cultured human dermal papilla cells secrete AM in significant amounts. The increased production of AM by beard cells in the presence of testosterone suggests that AM may have a significant role in androgendependent hair growth. Since phenol red also has a stimulatory effect on AM secretion, future studies should consider its effect on the production of mitogenic factors by cultured dermal papilla cells.