当归多糖对C57BL/6小鼠毛囊及毛发生长的影响

正脱发在日常生活中极为多见,临床可见的脱发性疾病类型也较多,包括脂溢性脱发、斑秃、药物诱导的生长期脱发等~([1])。近年来随着生活工作压力的增大以及人们对自身外表要求的提高,因脱发性疾病带来的心理与精神压力对人们的日常生活产生严重负面影响,对改善脱发的需求也日益增加,但临床对于脱发的治疗手段仍是有限的,且脱发性疾病的病理生理机制仍待探究。当归是著名的中草药之一,凭借其等广泛的药理活性在现代临床心脑血管、抗肿瘤、血液系统疾病、消化系统疾病、妇科疾病等方面也得到了诸多的应用~([2,3])。     

Scratching behavior in various strains of mice

Scratching behavior was induced in 12 strains of mice and the frequency was compared. An injection of histamine at a dose of 50 nmol induced frequent scratching behavior only in ICR mice, although the same dose of serotonin induced frequent scratching behavior in all strains of mice except for A/J. Histamine (10 nmol), serotonin (1 nmol), substance P (50 nmol) and passive cutaneous anaphylaxis induced significant vascular permeability increase in BALB/c, ICR, ddY and NC/Nga mice. These four stimuli also induced frequent scratching behavior in ICR mice. However, they failed to induce substantial increase in the incidence of scratching in the other three strains, except for ddY, which exhibited a slight but significant increase against substance P injection. These results suggest that the ICR mouse is a good responder for scratching behavior against various stimuli, especially against histamine. Thus ICR mice may be suitable for studying mediators and/or mechanisms for itching.     

甲状旁腺激素对小鼠毛发周期和毛发生长的影响

以C57BL6小鼠作为动物模型,观察甲状旁腺激素(PTH)的多肽片段PTH(7～34)和PTH(1～34)对毛发周期和毛发生长的影响。用松香/蜡混合物拔毛法诱导C57BL6小鼠毛发由休止期进入生长期,拔毛同时腹腔注射PTH(7～34),持续19天,观察毛发周期的变化。结果,PTH(7～34)组小鼠在拔毛后第5天毛发进入生长期,比对照组提前24h左右;至第19天,对照组小鼠多数毛发进入退行期或休止期,而PTH(7～34)组仍有大部分毛发维持在生长期。C57BL6乳鼠触须毛囊体外培养结果,加PTH(7～34)10-6mol/L浓度组和10-7mol/L浓度组毛干生长速度显著比对照组加快(P<0.01);而PTH(1～34)10-9mol/L浓度组毛干生长明显慢于对照组(P<0.01)。提示PTH的不同片段对毛发生长有不同影响,PTH(7～34)可延长毛发生长期,促进小鼠毛发生长,而PTH(1～34)则对毛发生长有抑制作用。     

Effect of hair growth cycles on experimental cutaneous candidiasis in mice

Experimental cutaneous Candida albicans infections were produced in mice by inoculating the organisms onto areas of shaved flank skin where the hair follicles were in either the anagen (growing) or telogen (resting) phase of the growth cycle. Infection with Candida occurred in a majority of animals inoculated on either anagen or telogen skin, and the rate of clearance of the organisms was equivalent for infections on the 2 types of skin. Some of the animals inoculated on anagen skin developed foci of Candida infection in the well-developed hair follicles, below the skin surface. Deep foci of infection were not found after inoculation of the telogen areas. The infections resulted in increases in epidermal thickness and sensitization of the animals to Candida antigens, but these responses were not different between animals inoculated on the 2 types of skin. The results of these experiments indicate that although Candida albicans can infect skin containing either active or resting hair follicles, foci of infection below the skin surface occur only when well-developed hair follicles are present. These findings may have relevance to the consequences of human cutaneous candidiasis.     

Cyclosporin A-induced hair growth in mice is associated with inhibition of hair follicle regression

Background Cyclosporin A (CsA) often causes hair growth in transplant recipients. Our objectives were to evaluate the effect of CsA on follicular hair keratinocyte growth in nude mice by assessing their proliferation in vivo, and to assess the ability of CsA to prevent follicular keratinocyte apoptosis in vivo and chemotherapy-induced keratinocyte apoptosis in vitro.Methods Nude mice were fed various daily doses of CsA (10–100 mg/kg). Dorsal skin sections stained with hematoxylin and eosin, followed by immunostaining with 4-deoxybromouridine, were examined for determination of hair follicle number and hair follicle keratinocyte proliferation. Follicular keratinocytes were isolated and examined for apoptotic status. Apoptosis was induced in vitro in a keratinocyte cell line by 4-hydroperoxycyclophosphamide. The antiapoptotic effects of various CsA concentrations (0.1–5 g/ml) were measured by annexin-V/propidium iodide binding.Results CsA caused a dose-dependent increase in the number of hair follicles but had no effect on follicular keratinocyte proliferation. Treatment with CsA decreased the number of apoptotic follicular keratinocytes. In vitro, there was a dose-dependent inhibition of the extent of early and late apoptosis of treated keratinocytes.Conclusion CsA may induce hair growth by increasing the number of hair follicles and inhibiting apoptosis of follicular keratinocytes, thereby delaying hair follicle regression.     

Topical minoxidil counteracts stress-induced hair growth inhibition in mice

Stress has long been suspected as a possible cause of hair loss in various species, even though convincing experimental evidence has not been available. Recently, we have shown in a murine model that sonic stress alters hair growth and cycling in vivo, and have postulated the existence of a 'brain-hair follicle axis' (BHA). In order to study whether a clinically available and widely used topically active hair growth stimulator mitigates stress-triggered hair growth inhibition in this stress model, we have applied a 5% minoxidil solution. Female CBA/J mice were depilated and randomized in to two groups: control (n = 20) and sonic stress (n = 20). These groups were further divided and either treated daily with 5% minoxidil solution or vehicle alone. The stress group was exposed to sonic stress for 24 h starting 14 days after anagen induction by depilation. All mice were sacrificed 16 days after the depilation and assessed by quantitative histomorphometry. Sonic stress significantly increased the number of hair follicles with apoptotic cells and inhibited intrafollicular keratinocyte proliferation. In addition, the number of clusters of perifollicular MHC class II+ cells and degranulated perifollicular mast cells was significantly enhanced in the stressed mice. In accordance with previous findings, all stressed mice showed an advanced hair cycle progression towards catagen. All of these stress-induced hair growth inhibitory changes along the BHA were down-regulated by topical minoxidil application. This encourages one to explore clinically whether topical minoxidil is a safe and effective pharmacologic tool for the management of stress-associated telogen effluvium in humans.     

Effects of two chronic stresses on mental state and hair follicle melanogenesis in mice

Growing bodies of data show that psychological stress can be associated with hair loss and vitiligo. Researchers have revealed that stress could indeed inhibit hair growth in vivo, but the relationship between chronic stress and melanogenesis remains unknown. In this study, we established two types of stress models, chronic restraint stress (CRS) and chronic unpredicted mild stress (CUMS) mice models, and explored the possible role of stress in mice hair follicle melanogenesis. We found that stress changed hippocampal morphology, decreased 5‐HT level in brain and skin and down‐regulated 5‐HT1A receptor expression in hippocampal CA1 region and skin. The alterations of 5‐HT and 5‐HT1A receptor might be a threshold of central stress to associate with the behaviour changes. Both two stresses caused cellular damage of melanocytes and inhibition of keratinocytes proliferation in HF, which made the synthetic pigment loss. CRS which was considered primarily as a “psychological” stressor had the lower melanin production in HF, as well as the level of 5‐HT in skin was down‐regulated more than those in CUMS group.     

血管生成素在人毛囊中的表达及其对毛发生长的影响

目的 探讨血管生成素在人毛囊中的表达及其意义。方法 分离完整的人生长期毛囊,提取总RNA,RT-PCR法检测血管生成素mRNA的表达,同时应用免疫组化法检测血管生成素蛋白在人毛囊中的表达。在此基础上,在体外培养的人毛囊中加入不同浓度的重组人血管生成素（0 ～ 200 ng/mL）,培养6 d后测量毛囊的生长长度。利用两步酶法分离培养人毛乳头细胞,加入不同浓度的重组人血管生成素（0 ～ 200 ng/mL）,48 h后,MTT法检测细胞增殖,流式细胞仪检测细胞周期。结果 RT-PCR显示人毛囊表达血管生成素mRNA,免疫组化法发现人毛囊的毛乳头和真皮鞘表达血管生成素蛋白。25 ～ 200 ng/mL重组人血管生成素呈浓度依赖性促进体外培养的人毛囊生长（P < 0.05）,而12.5 ～ 200 ng/mL重组人血管生成素能够明显促进体外培养的人毛乳头细胞增殖（P < 0.05）。流式细胞仪检测12.5 ～ 200 ng/mL重组人血管生成素能够显著增加S期细胞比率和细胞增殖指数（P < 0.05）。结论 血管生成素可能是一种促进毛发生长的因子。     

Tamoxifen‐loaded liposomal topical formulation arrests hair growth in mice

Background For several decades, androgens have dominated endocrine research in the domain of hair growth control. However, it has long been known that oestrogens also tend to alter hair follicle (HF) growth and cycling significantly by binding to locally expressed high‐affinity oestrogen receptors (ORs). Tamoxifen (TAM) is a selective OR modulator. Objectives The current work aims to investigate the effect of topically applied TAM on the hair growth of mice. Methods Test formulations were applied once daily on the shaved back area of the mice for a period of 5 weeks. The effect of these formulations was studied by visual and histological examinations. Results Animals treated with saline and placebo gel formulation showed significant hair growth on the 20th day. The number and length of follicles were also found to be normal. In contrast, no hair growth was observed in the animals treated with TAM gel, even after the termination of treatment. The HFs were found to be arrested in telogen phase with clear signs of follicle dystrophy. Conclusions The hair growth‐retarding effect of TAM observed in the current study clearly demonstrates its OR agonistic effect on hair growth. This work also provides a distinct lead towards the possible potential of TAM liposomal gel in the treatment of hirsutism.     

拉坦前列素对人头皮毛囊毛发生长的影响

目的:研究拉坦前列素对人头皮毛囊毛发生长状况变化的影响。方法:选取体外培养成功的毛囊120根,随机分为6组:空白对照组、试验组四组(分别加0.005%、0.001%、0.0005%、0.01%拉坦前列素)、阳性对照组(加米诺地尔125μg/mL)每组20根,培养14天。以显微镜目镜测微器测量毛囊长度。每组选取6根毛囊,掺入3H-TdR后,置于闪烁杯中液闪记数。结果:0.005%和0.001%拉坦前列素组毛囊毛发生长速度较其它组快,0.01%拉坦前列素组较其它组慢,差异有统计学意义;同位素3H-TdR摄入率值的比较结果与毛囊生长长度一致。结论:拉坦前列素对人头皮毛囊毛发生长的作用取决于药物浓度(低浓度起促进作用,高浓度起抑制作用);可能的机制为促进毛囊生长,抑制毛囊进入休止期。