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1.
The canine hair cycle - a guide for the assessment of morphological and immunohistochemical criteria
The hair follicle has a lifelong capacity to cycle through recurrent phases of controlled growth (anagen), regression (catagen) and quiescence (telogen), each associated with specific morphological changes. A comprehensive classification scheme is available for mice to distinguish the cycle stages anagen I-VI, catagen I-VIII and telogen. For dogs, such a classification system does not exist, although alopecia associated with hair cycle arrest is common. We applied analogous morphological criteria and various staining techniques to subdivide the canine hair cycle stages to the same extent as has been done in mice. Of all the staining techniques applied, haematoxylin and eosin stain, Sacpic, Masson Fontana and immunohistochemistry for vimentin and laminin proved to be most useful. To evaluate the applicability of our criteria, we investigated skin biopsies from healthy beagle dogs (n=20; biopsies from shoulder and thigh) kept in controlled conditions. From each biopsy, at least 50 hair follicles were assessed. Statistical analysis revealed that 30% of the follicles were in anagen (12% early and 18% late), 8% in catagen (2% early, 5% late and 1% not determinable) and 27% in telogen. Thirty-five per cent of hair follicles could not be assigned to a specific cycle stage because not all follicles within one biopsy were oriented perfectly. In conclusion, this guide will not only be helpful for the investigation of alopecic disorders and possibly their pathogenesis, but may also serve as a basis for research projects in which the comparison of hair cycle stages is essential, e.g. comparative analysis of gene expression patterns. 相似文献
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Credille KM Slater MR Moriello KA Nachreiner RF Tucker KA Dunstan RW 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2001,15(6):539-546
The effects of hypothyroidism on canine skin were determined by comparing morphologic, morphometric, and hair cycle differences in skin biopsy samples from 3 groups of age- and gender-matched Beagle dogs: (1) euthyroid dogs; (2) dogs made hypothyroid by administration of 131I; and (3) dogs made hypothyroid and maintained in a euthyroid state by treatment with synthetic thyroxine. After 10 months of observation, there was slower regrowth of hair 2 months after clipping in the untreated-hypothyroid dogs. Untreated-hypothyroid dogs had a greater number of follicles in telogen and fewer hair shafts (ie, a greater number of hairless telogen follicles) than did the control group. The control dogs had a greater number of telogen follicles but the same number of hair shafts as the treated-hypothyroid group. Treated-hypothyroid dogs had the greatest number of follicles in the growing stage of the hair cycle (anagen). This study suggests that, at least in Beagles, induced hypothyroidism does not affect the pelage as dramatically as has been described in naturally occurring disease. This is because normal Beagles retain hair shafts in follicles for long periods, and the alopecia of hypothyroidism appears to evolve slowly because of the prolongation of this haired telogen stage. The evaluation of thyroxine-treated hypothyroid dogs demonstrates that thyroid hormone supplementation of Beagle dogs with induced hypothyroidism stimulates hair growth. 相似文献
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Histology of the hair cycle in male beagle dogs 总被引：1，自引：0，他引：1
F K Al-Bagdadi C W Titkemeyer J E Lovell 《American journal of veterinary research》1979,40(12):1734-1741
A detailed histologic study of the hair follicles of male Beagle dogs was made to determine changes in microscopic structure associated with the three stages in the hair cycle. Observed changes are that the bulbs of hair follicles in anagen are more closely associated with adipose tissue than they are in telogen. This is due to the deeper penetration of the follicles into the subcutaneous tissue during anagen. The hair germ cells of telogen were presumed to arise from the stratum basale of the matrix cells rather than from the outer root sheath cells. During telogen, the dermal papilla is separated from the club hair, but remains in close proximity to it. There is no connecting stalk as is reported for other animals. 相似文献
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皮肤切片采用HE染色方法,对辽宁绒山羊常年长绒型品系和季节长绒型品系皮肤表皮厚、真皮厚、次级毛囊和初级毛囊深度、密度,次级毛囊和初级毛囊毛球宽度,S／P值等作了详细统计观察,从形态学方面研究了辽宁绒山羊皮肤毛囊在1年内的变化规律。结果表明：两品系辽宁绒山羊毛囊的兴盛期为4～10月,退行期为11～12月,休止期为1～3月,持续时间分别为7、2、3个月。兴盛期经历时间最长,退行期最短。但在毛囊的退行期,因为大多数毛囊的活性还很高,因此在退行期绒毛仍在生长,特别是在退行前期（10、11月份）还是绒毛的快速生长期。 相似文献
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The literature reviewed has revealed differences of opinion concerning the location of alkaline phosphates and its relationship to the hair cycle stages. This project was undertaken to determine alkaline phosphatase activity in the hair follicle stages: anagen, catagen, and telogen. Skin biopsy samples were collected over a period of 1 year from 9 purebred male Beagle dogs. At the beginning of the experiment 3 dogs were 2 weeks of age, 3 dogs were 12 months of age and 3 dogs were 21 months of age. The skin biopsies were taken monthly from alternate sides of each animal near the thoracolumbar region. Samples were fixed in 80% chilled alcohol and the alkaline phosphatase activity was determined by Gomori's calcium cobalt method. A total of 250 slides with seven sections per slide was examined. Each slide contained between 14–60 hair follicles. During anagen stage, the reaction of the dermal papilla for the presence of alkaline phosphatase was variable. A weak or negative reaction was observed in this study which was an unexpected finding. The reaction of the dermal papilla to alkaline phosphatase was positive in catagen stage. The cells of the dermal papillae in telogen stage were strongly alkaline phosphatase positive. The reaction was not confined to the blood vessels but occurred in all parts of the dermal papilla in both early and late stages. 相似文献
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The purpose of this study was to evaluate oestrogen receptor alpha staining in a variety of breeds and skin conditions. The influence of inflammation and coat type on the presence and intensity of oestrogen receptor alpha staining was evaluated. Approximately 1700 haematoxylin and eosin (H&E)-stained slides of skin biopsies were screened for presence of small hair bulbs. Slides from 94 cases were submitted for oestrogen receptor alpha immunohistochemistry. H&E-stained skin biopsy tissues were examined for inflammation and hair follicle stages. Oestrogen receptor alpha staining characteristics of telogen follicles, flame follicles, large anagen bulbs, small hair bulbs and early anagen hairs (capped bulbs) were recorded. To assess the influence of inflammation and coat type on oestrogen receptor staining of hair follicle types, chi-square tests, Fisher's exact tests and logistic regression models were performed. Slides were classified as inflammatory (65) and noninflammatory (29). There were no statistically significant differences in oestrogen receptor staining when comparing inflammatory to noninflammatory skin biopsies or skin biopsies from dogs with different coat types. A subset of 13 noninflammatory biopsies from alopecic skin was identified. There was a statistically significant increase in the number of flame follicles in this subset as compared to all others. Comparison of oestrogen receptor staining of hair follicle types from these biopsies and all other biopsies revealed a statistically significant increase in the number of mature telogen hair follicles stained in this subset. No statistical difference in staining of early follicle stages was noted. Therefore, the oestrogen receptor is unlikely to be the controlling factor for the transition from telogen to anagen in the dog. 相似文献
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The impact of anatomic location on trichogram analysis of the hair cycle phases was evaluated in 15 clinically normal dogs. The purposes of this study were to determine if the number of hairs in anagen and telogen vary among anatomic sites within a dog and to see whether there is an optimal region to sample hairs for canine trichogram evaluation of the hair cycle phases. In each dog eight sites were sampled. Four (26.7%) of the 15 dogs had no significant differences in the number of hairs in anagen and telogen among the eight body sites examined. Nine (81.8%) of the remaining 11 dogs had only one site that revealed significant differences in the number of hairs in anagen or telogen. In seven (77.8%) of these dogs only the anagen differed significantly, and in two (22.2%) dogs both phases differed significantly. Two (18.2%) dogs revealed two sites with significant differences in the number of hairs in anagen. The number of hairs in anagen and telogen in the shoulder area did not vary significantly in any of the dogs. This observation, coupled with the ease of sampling at this site, indicates that the shoulder is the site of choice when studying variations in ratios of hair cycle phases using unit area trichogram. Our results also suggest that numbers of telogen and anagen hairs from body regions with different hair shaft lengths do not vary significantly, and the occasional inconsistent results noted at some body sites might be due to sample collection technique. 相似文献
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本实验旨在研究Wnt10b在内蒙古成年绒山羊皮肤中的表达变化规律和褪黑激素(MT)对其表达量的影响。每隔1个月按照2 mg/kg BW的剂量在受试内蒙古成年绒山羊耳后皮下埋植MT。连续采集12个月(从2009年8月到2010年7月)的肩胛部皮肤样品,应用实时荧光定量PCR技术检测Wnt10b的表达量。结果表明:Wnt10b在内蒙古成年绒山羊皮肤组织中毛囊生长中期和休止前期高表达;埋植MT提高了Wnt10b在内蒙古成年绒山羊皮肤组织中毛囊休止期和退行期的表达量。结果提示,Wnt10b参与内蒙古绒山羊毛囊生长的信号传递过程,并在退行期和休止期转变过程中发挥作用;Wnt10b参与了外源MT促绒毛生长的毛囊周期性变化过程。 相似文献
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To determine whether pituitary concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) or hypothalamic content of gonadotropin releasing hormone (GnRH) change before puberty, 40 prepubertal gilts averaging 7 mo of age were slaughtered before or on the second, third or fourth day after relocation and boar exposure. Some gilts responded to relocation and boar exposure as indicated by swollen vulvae, turgid uteri and enlarged ovarian follicles at the time of slaughter. Pituitary concentrations of LH and FSH and hypothalamic content of GnRH were similar between gilts that responded to relocation and boar exposure and gilts that did not respond. In addition, boar exposure and relocation had no effect on pituitary concentrations of LH and FSH or on hypothalamic content of GnRH. To determine whether pituitary responsiveness to GnRH changes before puberty, a third experiment was conducted in which 72 gilts were injected with 400 micrograms of GnRH either before or on the second, third or fourth day after relocation and boar exposure. In gilts that subsequently responded (i.e., ovulated) as a result of relocation and boar exposure, pituitary responsiveness to GnRH was reduced as compared with gilts that failed to ovulate after relocation and boar exposure. Peak concentrations of serum LH after GnRH injection were 4.6 +/- 1.3 vs 9.8 +/- .8 ng/ml for responders vs nonresponders. Peak serum FSH after GnRH injection was also lower for responders than for nonresponders (29.5 +/- 4.2 vs 41.2 +/- 2.4 ng/ml). When compared with controls, relocation and boar exposure did not significantly affect GnRH-induced release of LH and FSH.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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The role of oestrogen receptors in dogs with hair cycle arrest (alopecia X) was investigated by immunohistochemistry. The purpose of this study was to determine if hair regrowth in dogs with hair cycle arrest treated with melatonin was associated with a decrease in follicular oestrogen receptors. Fifteen Pomeranians (excluding intact females) with hair cycle arrest were enrolled. Two biopsies were obtained from alopecic areas of the trunk before and after 3 months on melatonin. Haematoxylin and eosin-stained tissues were examined and oestrogen receptor-alpha was demonstrated immunohistochemically. Common histopathological findings included hyperkeratosis, follicular keratosis, excessive tricholemmal keratinization (flame follicles), thin epidermis, few small anagen bulbs, epidermal pigmentation and melanin aggregates within follicular keratin. Melanin aggregates within basal cells and hair were an occasional finding. After 3 months, 40% (six) dogs had mild to moderate hair regrowth. Biopsies from six dogs showed histological evidence of an increase in anagen hairs and eight dogs had a decrease in epidermal pigmentation. Moderate to marked staining intensity of oestrogen receptor-alpha was noted in all sebaceous gland basal cells, all small hair bulbs and follicular epithelium of telogen hairs. There was no oestrogen receptor-alpha staining of nuclei within the epidermis, apocrine glands or dermal fibroblasts. Large anagen hair bulbs had minimal to no oestrogen receptor staining. Hair regrowth was not associated with a change in oestrogen receptor-alpha staining. 相似文献
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LIU Bin GUO Jun Wudubala MA Yue-jun XIN Lei-yong ZHAO Cun-fa LI Yu-rong YIN Jun 《中国畜牧兽医》2017,44(4):994-1000
In order to extend the anagen of cashmere goat hair follicles and increase the production of cashmere,this study was performed with artificially shorten the daylight time among Arbas White cashmere goats. Skin tissue sections from cashmere goats were collected to compare the morphologic changes between artificial daylight and natural daylight,and immunohistochemical method was used to study the hair follicle cell proliferation and important protein expression in related signaling pathways. The results showed that strong cell proliferation occurred in cashmere goat hair follicle cells during artificial daylight,plenty of cytokeratin 15 (K15) positive signals were distributed in the outer root sheath,β-catenin protein was actively expressed in hair matrix and root sheath, indicating that the hair follicles were in the anagen growth phase;Meanwhile,cashmere goat hair follicles under natural daylight were in telogen with weak signals. Above all prove that short photoperiod played an important role in promoting hair follicle growth,the artificial short photoperiod could change hair follicle growth cycle and make hair follicles earlier enter to the anagen growth phase,causing a variety of typical gene expressions during hair follicle growth. 相似文献
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为了延长绒山羊毛囊兴盛期,提高羊绒产量,本试验通过人工缩短内蒙古阿尔巴斯型绒山羊的日照时间,利用组织切片技术对比人工短光照和自然光照周期下绒山羊皮肤组织形态变化,利用免疫组织化学方法研究毛囊细胞增殖及相关信号通路重要蛋白的表达。结果显示,人工短光照周期下绒山羊毛囊细胞增殖强烈,干细胞标记角蛋白15（cytokeratin 15,K15）阳性信号大量分布于外根鞘,β-catenin信号活跃表达于毛母质及根鞘,毛囊提前进入兴盛期;而自然光照周期下绒山羊毛囊仍停留在休止期,相应蛋白信号表达较弱。综上表明,短日照对毛囊生长具有明显的促进作用,人工短光照周期可以提前激活毛囊干细胞,使其提前进入兴盛期,引起多种毛囊生长相关蛋白的表达。 相似文献
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Hair cycle activity has been extensively studied in humans, sheep and laboratory animals, but there is a lack of information in dogs. Besides varying according to species, breed, sex and general health, hair growth is mainly affected by climatic variations. The aim of the study was to evaluate the follicle activity in three breeds of dogs with different hair types, in the city of Viçosa, Minas Gerais (latitude 20°45′S), Brazil. Twenty‐one male dogs of boxer, labrador and schnauzer breeds were trichographically analysed monthly over 12 consecutive months. Hair percentage of telogen and anagen hairs at the different stages of the hair cycle in boxers and labradors was not significantly different, but both differed from the schnauzers. A significant correlation between hair follicle cycle and environmental temperature and photoperiod was noted in the boxers and labradors. In these breeds, a larger number of telogen hairs were observed during the hottest months of the year, and an increase in anagen hairs during the coldest months. The mean percentage of telogen hairs was 93, 90 and 55.3% for boxer, labrador and schnauzer, respectively. 相似文献
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Dr. S. H. Arslan C. P. Mackenzie R. Brown J. T. Baxter 《Veterinary research communications》1983,6(1):51-58
The stage of hair growth which predominated in dogs not affected with hypothyroidism appeared to be breed-dependent. For example, in boxers, Labradors and collies, the resting stage (telogen) predominated, whereas in West Highland White terriers and cairn terriers the active stage (anagen) predominated. However, even in pet dogs kept mainly indoors, the proportion of hairs in anagen tended to increase during the winter months.In dogs affected with hypothyroidism, the proportion of hairs in anagen or telogen in members of a particular breed was the same as in the normal dogs of the breed. From this, it appeared that breed was more influential than hypothyroidism in determining the predominant phase of hair growth. 相似文献
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毛囊的周期性变化和分子调控及其在绒山羊上的研究进展 总被引：4，自引：1，他引：3
毛囊是一个形态和结构较为复杂的皮肤附属器官,它控制着毛发的生长,具有自我更新和周期性生长的特点。毛囊的周期性变化依靠毛囊上皮细胞和真皮间充质细胞的相互作用,先是毛囊长出毛干为生长期,接下来是凋亡驱动的退行期,然后进入休止期。其变化过程是一系列信号分子相互作用形成的,包括启动信号、维持毛囊生长的信号及抑制毛囊生长的信号等。绒山羊初级毛囊和次级毛囊在出生后也表现周期性变化,次级毛囊由于光周期的影响而呈很强的季节性的周期变化,而初级毛囊则变化不明显。山羊绒是绒山羊次级毛囊的衍生物,次级毛囊的生长发育直接影响山羊绒的产量和品质。因此,研究皮肤毛囊周期性变化的规律及它们的分子调控机理不仅可揭示毛囊的发育规律而且对绒山羊的育种具有重要指导意义。 相似文献
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The hormone GnRH has a stimulatory effect on gonadotropin synthesis and secretion. The objective of the first study was to evaluate concentrations of FSH and LH in plasma of boars after successive treatment with SB75, a GnRH antagonist. Thirteen boars greater than 1 yr of age (eight White Composite [WC] and five Meishan [MS]) were injected once daily with SB75 (10 microg/kg of body weight) for 4 d. Plasma concentrations of LH and testosterone (T) decreased after 1 h from the first dose of SB75. After 12 h of treatment, LH gradually returned to pretreatment concentrations, but T remained suppressed (< 2 ng/mL) until after the last injection of SB75. There was a modest, but significant, reduction in FSH during treatment with SB75. The prolonged inhibitory effect of SB75 on suppression of plasma T concentrations, in the presence of pretreatment concentrations of LH, implied direct effects of SB75 at the testis. In the second experiment, testicular tissue from adult boars was incubated in the presence of three doses of human chorionic gonadotropin (hCG; 0, .5, and 5 IU) with SB75 (250 ng/mL) or with Deslorelin, a GnRH agonist (500 ng/mL). Samples of media were collected every hour for 3 h, and concentrations of T and estrone (E1) were determined by RIA. Concentrations of T and E1 increased with time in response to treatment with hCG. Co-treatment with SB75 decreased media concentrations of T (P < .01) and E1 (P < .03) compared to controls (77.9 vs 85.7 +/- 2.0 and 4.7 vs 5.3 +/- .2 ng/g). In contrast, treatment with Deslorelin had no effect on the amount of T (P > .50) or E1 (P > .26) released with all dosages of hCG. These results indicate that a GnRH antagonist has a direct effect on the testis, decreasing amounts of T and E1 released from the Leydig cells; however, treatment with a GnRH agonist had no direct effect on release of these gonadal steroids. Thus, it remains unresolved whether the site of action of GnRH antagonist on testicular steroidogenesis is through a testicular GnRH receptor or through some other mechanism. 相似文献