562 Neuroendocrinology of human scalp hair follicles: Growth hormone-releasing hormone (GHRH) stimulates hair growth and controls a fully functional intrafollicular hypothalamic-pituitary-somatotropic (HPS) signaling axis

Abstract

Human scalp hair follicles (HFs) are a major non-classical site of neurohormone production. While we had previously shown that growth hormone (GH), unexpectedly, inhibits female human scalp HFs growth ex vivo, it is unknown whether human HFs also produce key HPS axis neurohormones themselves, i.e. GH, its upstream regulator, GHRH, and/or the negative feedback control, somatostatin (SST), and whether GHRH modulates hair growth. To answer these questions, human scalp HFs were organ-cultured and stimulated with human GH (100 or 300ng/mL), GHRH (100 or 300ng/mL), or vehicle for mRNA or protein analysis of key HPS axis elements.