Dermatology Research Centre, Salford Royal Hospital, The University of Manchester, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, Manchester, UK.
Br J Dermatol. 2013 Mar;168(3):520-5. doi: 10.1111/bjd.12113. Epub 2012 Dec 12.
Although there are clinical reports of hair loss associated with levodopa and dopamine agonists, it is unclear whether dopamine exerts any direct effects on the human hair follicle (HF).
Given the widespread use of dopamine agonists and antagonists in clinical medicine, we sought to determine whether dopamine exerts direct effects on human HF growth and/or pigmentation in vitro, and whether human HFs express dopamine receptors (DRs).
Microdissected human scalp HFs from women were treated in serum-free organ culture for 7 days with dopamine (10-1000 nmol L ), and the effects on hair shaft production, HF cycling (i.e. anagen-catagen transition), hair matrix keratinocyte proliferation and apoptosis, and HF pigmentation were measured by quantitative (immuno-) histomorphometry.
Dopamine had no consistent effect on hair shaft production, but did promote HF regression (catagen). It was also associated with significantly reduced proliferation of HF matrix keratinocytes (P < 0·01) and reduced intrafollicular melanin production. Dopamine receptor transcripts were identified in HFs and skin.
These data provide evidence that dopamine is an inhibitor of human hair growth, via the promotion of catagen induction, at least in vitro. This may offer a rational explanation for the induction of telogen effluvium in some women treated with dopamine agonists such as bromocriptine. Moreover, dopaminergic agonists deserve further exploration as novel inhibitors of unwanted human hair growth (hirsutism, hypertrichosis).
虽然有左旋多巴和多巴胺激动剂相关脱发的临床报告，但多巴胺是否对人类毛囊（HF）有直接影响尚不清楚。
鉴于多巴胺激动剂和拮抗剂在临床医学中的广泛应用，我们试图确定多巴胺是否在体外对人毛囊生长和/或色素沉着有直接影响，以及人毛囊是否表达多巴胺受体（DRs）。
从女性头皮中分离出微切割的人头皮毛囊，在无血清器官培养中用多巴胺（10-1000 nmol/L）处理 7 天，通过定量（免疫）组织形态计量学测量对毛干产生、HF 周期（即生长期-退行期过渡）、毛基质角质形成细胞增殖和凋亡以及 HF 色素沉着的影响。
多巴胺对毛干产生没有一致的影响，但确实促进了 HF 的退化（退行期）。它还与 HF 基质角质形成细胞增殖显著减少（P<0.01）和毛囊内黑色素产生减少有关。在毛囊和皮肤中鉴定出多巴胺受体转录本。
这些数据提供了证据，表明多巴胺通过促进退行期诱导，是人类毛发生长的抑制剂，至少在体外是这样。这可以为一些接受多巴胺激动剂（如溴隐亭）治疗的女性中诱导休止期脱发提供合理的解释。此外，多巴胺能激动剂值得进一步探索，作为抑制不必要的人类毛发生长（多毛症、多毛症）的新型抑制剂。
