Analysis of the age-related composition of human skin collagen and collagens synthesized by fibroblast culture

Age-related differences in the composition and the post-translational modifications of human skin collagens were examined in the present study. The data were compared with results of collagen synthesis from in vivo-aged fibroblasts in culture. Skin extracts and newly synthesized collagen from fibroblast cultures derived from both old and young donor groups showed the same ratio of collagen III to collagen I. Furthermore, no difference was noted in the degree of prolyl and lysyl hydroxylation of collagen I and collagen III. Young and old fibroblasts synthesized a similar quantity of collagen in vitro. The data suggest that fibroblasts maintain a uniform level of collagen production, composition and modification independent of the age of the donor.     

雌激素与皮肤老化的研究进展

雌激素对皮肤有重要的影响,其相对减少可加重皮肤的内源性和外源性衰老.一定量的雌激素能通过增加皮肤的厚度、水分和弹性,减少皮肤皱纹,防止皮肤老化.因此雌激素是治疗皮肤老化的有效方法之一.局部外用雌激素治疗皮肤老化的疗效与安全性已经肯定,而雌激素替代疗法治疗皮肤老化的疗效还有待进一步研究证实.     

吡咯喹啉醌对小鼠年龄相关皮肤衰老的延缓作用及机制研究

【摘要】 目的 研究吡咯喹啉醌对小鼠年龄相关皮肤衰老的作用及机制。方法 将昆明种小鼠SPF级喂养,分为3组,每组10只,年轻组用普通饮食喂养8个月,年老组用普通饮食喂养20个月构建小鼠自然衰老模型,吡咯喹啉醌组在每公斤普通饮食饲料中添加吡咯喹啉醌4 mg喂养20个月。喂养结束后,取各组小鼠背部皮肤组织,HE染色检测皮肤表皮和真皮厚度;Masson染色检测皮肤总胶原变化;免疫组化检测增殖蛋白Ki67表达变化;透射电镜检测皮肤自噬体变化;Western印迹检测自噬相关蛋白Beclin1、LC3Ⅱ/LC3Ⅰ、p62表达变化,各组间比较采用单因素方差分析,组间两两比较采用LSD-t检验。结果 HE和Masson染色显示,年老组表皮厚度［（15.67 ± 0.36） μm］和真皮厚度［（87.95 ± 11.86） μm］以及总胶原阳性百分率［（22.12 ± 1.72）%］均显著低于年轻组［（29.37 ± 0.25） μm、（264.93 ± 10.34） μm、（45.03 ± 1.54）%,均P＜0.05］,而吡咯喹啉醌组表皮厚度［（25.53 ± 0.47） μm］和真皮厚度［（145.01 ± 9.71） μm］以及总胶原阳性百分率［（31.17 ± 1.20）%］较年老组增加（均P＜0.05）。免疫组化结果显示,年老组皮肤增殖蛋白Ki67阳性细胞表达率［（13.74 ± 3.06）%］低于年轻组［（29.07 ± 2.79）%,P＜0.05］和吡咯喹啉醌组 ［（21.20 ± 1.47）%,P＜0.05］。透射电镜观察显示,年老组与年轻组比较,皮肤自噬体数量增加（P＜0.05）,吡咯喹啉醌组自噬体数量较年老组减少（P＜0.05）。Western印迹实验显示,与年轻组比较,年老组Beclin-1表达降低（P＜0.05）,LC3Ⅱ/LC3Ⅰ比值下降（P＜0.05）,p62表达升高（P＜0.05）;而吡咯喹啉醌组与年老组比较,Beclin1表达升高（P＜0.05）,LC3Ⅱ/LC3Ⅰ比值增加（P＜0.05）,p62表达降低（P＜0.05）。结论 吡咯喹啉醌能够延缓小鼠皮肤衰老,其机制可能与增加小鼠皮肤细胞增殖能力和促进皮肤自噬水平相关。     

胶原蛋白肽抗皮肤自然老化作用机制与临床研究进展

近年来胶原蛋白肽(CP)成为延缓皮肤自然老化的研究热点。动物实验证明, CP可通过促进胶原蛋白合成、抑制胶原蛋白降解和提高抗氧化酶活性修复自然老化皮肤。细胞实验证明, CP可通过刺激核因子κB信号通路和转化生长因子β/Smad信号通路促进成纤维细胞增殖和胶原蛋白、弹性蛋白合成。临床研究表明, 长期口服补充CP或CP联合其他具有抗氧化活性物质可改善皮肤含水量并降低皮肤经皮水分散失, 改善皮肤皱纹和弹性, 还可改善皮肤胶原纤维结构、真皮和表皮质量及面部皮肤的整体状况。本文对皮肤自然老化机制和近年来CP修复自然老化皮肤的作用机制研究进行综述, 以期为临床进一步研究并应用CP修复自然老化皮肤提供理论依据。     

High expression level of homocitrulline is correlated with seborrheic keratosis and skin aging

BackgroudHomocitrulline (Hcit), is involved in the pathological processes of some diseases. However, the role and function of Hcit (CBL) in human skin remains largely obscure.ObjectiveTo investigate the correlation of the level of Hcit in seborrheic keratosis, skin aging, and its clinical significance.MethodsImmunohistochemistry was used to analyze the level of Hcit in skin lesions of seborrheic keratosis (SK), unaffected skin (distant 0.5 centimeters from SK lesion), and normal skin of healthy subjects in the control group. ELISA test was used to detect the serum level of CBL in SK patients and healthy subjects of different ages.ResultsHcit was mainly localized in the nucleus of epidermal cells. In healthy control skin, the expression of Hcit increased with age and showed a positive correlation with age (the correlation coefficient was 0.806, p = 0.0002). The expressional level of Hcit in SK lesions was higher than that in healthy control skin (Z = −3.703, p = 0.0002). The serum level of CBL in healthy subjects and in SK patients increased with age (the correlation coefficient were 0.5763, p = 0.0032; 0.682, p = 0.004. respectively). The serum level of CBL in SK patients was higher than that in healthy subjects (Z = −2.19, p = 0.030).Study limitationsThe small serum sample size in the study.ConclusionThe high expressional level of Hcit is correlated with seborrheic keratosis and skin aging. HCit may be one of the potential biomarkers of skin aging.     

Serum markers of collagen synthesis and degradation in skin diseases. Altered levels in diseases with systemic manifestation and during systemic glucocorticoid treatment

Serum concentrations of the markers of collagen synthesis and degradation, collagen I propeptide (PICP), collagen III propeptide (PIIINP) and the cross-linked telopeptide of type I collagen (ICTP) were measured in young male dermatological patients and in control subjects. No significant differences were noted between patients suffering from atopic eczema (n=24), other eczemas (n=11), acne (n=8), psoriasis (n=7) or tinea (n=9) and the control subjects (n=24). In the total study population representing patients with common skin diseases and control subjects there was a significant correlation between the serum concentrations of PICP and PIIINP and between the concentrations of PICP and ICTP. This suggests that synthesis of type I and III collagens in vivo is coordinated and that the degradation and synthesis of type I collagen is balanced. These markers were also measured in older patients suffering from psoriasis, eczema and various connective tissue diseases. It was noted that the degree of skin involvement in these diseases was not related to the serum concentrations of the markers of collagen metabolism. The highest levels of PICP and PIIINP were observed in a patient with systemic mastocytosis (PICP 309 g/1 and PIIINP 8.0 g/1). Increased levels of PIIINP were also found in patients with a high alcohol consumption. We have previously demonstrated that systemic glucocorticoids reduce collagen propeptide levels in serum. In the present study we also proved that systemic gluocorticoids have no effect on collagen degradation. Thus the side effects of glucocorticoids, such as growth inhibition, skin atrophy and decrease in bone mass, are a result of inhibition of the synthesis of collagen and other macromolecules. The results indicate that local or generalized skin diseases do not markedly alter serum markers of collagen synthesis or degradation. The alterations in collagen metabolism determined by measurements in serum are thus mostly related to systemic involvement and medication (especially glucocorticoids).     

UVA- and UVB-induced changes in hairless mouse skin collagen

UVA- and UVB-induced alterations in dermal collagen were investigated in a murine animal model. Groups of hairless mice were exposed to UVA and UVB for 28 weeks at a dose of 60 J/cm² three times weekly and 0.06 J/cm² three times weekly, respectively. Untreated animals were used as controls. Every 4 weeks dorsal skin was examined for quantitative and qualitative changes in dermal collagen. Neither UVA nor UVB caused a significant alteration in total skin collagen content. However, after UVA treatment the ability of skin collagen to be digested by pepsin decreased dramatically (up to 65% of skin collagen remained insoluble after 4 months), whereas exposure to UVB had no significant effect. Furthermore a shift in the ratio of 1(I,III) chains to 2(I) chains was detected after UVA exposure. The amount of type V collagen in mouse skin, as determined by a sensitive ELISA method, was markedly decreased after UVA treatment, but not after UVB treatment.This work was presented in part at the Jahrestagung der Arbeitsgemeinschaft Dermatologische Forschung 1988     

一种胶原基质全层皮肤模型的构建和表征

目的 构建一种体外维持时间长、有利于后续测试研究的胶原基质皮肤模型。方法 将猪胶原和正常人皮肤成纤维细胞混合接种于培养皿,培养得到真皮层结构后,将第3 ~ 7代正常人角质形成细胞接种于真皮层表面,培养得到双层皮肤模型。通过HE和Masson染色评估皮肤模型的形态和组织结构,使用电镜观察模型的超微结构,并通过免疫组化和免疫荧光染色观察模型中各层的主要标记物表达情况。结果 HE和Masson染色发现,皮肤模型与正常人皮肤组织有相近的真皮及表皮结构,且模型收获后仍具有稳定良好的真表皮结构,可在体外继续培养14 d。电镜下显示,皮肤模型中可见角质层中脂质、颗粒层中透明角质颗粒、角化桥粒、桥粒、基底膜等超微结构。免疫组化及免疫荧光显示,皮肤模型在表皮层中具有与正常皮肤一致的转谷氨酰胺酶、丝聚合蛋白、角蛋白10、Ki67的表达,基底膜具有与正常皮肤一致的Ⅳ型胶原和层黏连蛋白5表达,真皮层具有一致的Ⅰ型胶原、Ⅲ型胶原及原纤维蛋白表达。结论 本研究构建的三维皮肤模型组织结构和多种蛋白的表达与正常人体皮肤相似,模型收获后体外可继续稳定培养至少14 d。     

甲状旁腺激素相关蛋白与皮肤

甲状旁腺激素相关蛋白是与甲状旁腺激素同源的一种多肽类物质，二者结合于同一种细胞膜受体。甲状旁腺激素相关蛋白及其受体广泛分布于人体的各种组织，通过旁分泌或自分泌方式，对组织器官的发生、生长及分化过程发挥调节作用。甲状旁腺激素相关蛋白及其受体对人表皮的增殖分化、毛囊的发育及毛发的生长也有重要作用，可能成为相关皮肤病的一个新的药物治疗靶点。     

Inhibition of collagen expression by azelastine hydrochloride in cultured skin fibroblasts from normal individuals and scleroderma patients

The effects of azelastine hydrochloride on cell proliferation and collagen synthesis in cultured human skin fibroblasts were studied. Azelastine inhibited cell proliferation during proliferating cell phases. Azelastine was found to inhibit collagen synthesis without altering cell proliferation during quiescent phases. It did not alter the ratio of type I to III collagen synthesis. Northern blot analysis of collagen chain mRNAs revealed that the levels of α₁ (I), α₁ (III) and α₁ (VI) mRNAs were reduced by azelastine treatment, whereas the level of α₂ (VI), α₃ (VI) mRNAs were not significantly changed. These results suggest that azelastine modulates collagen synthesis at a pretranslational level. Azelastine inhibited collagen synthesis in fibroblasts from scleroderma patients to the same extent as in normal skin fibroblasts. This drug may be useful in the treatment of fibrotic diseases.     

246名女性皮肤老化特征及相关因素的调查分析

目的 探讨女性面部皱纹的发生情况及相关影响因素.方法 采用问卷表调查的方法,将研究对象根据工种及日均日晒时间分为室内组和室外组,使用图像分析仪SIA0612标准化拍照,结合Visioscan VC98定量测量皱纹的结果,将研究对象面部皱纹分0～9级分析.利用SPSS 17.0分析防晒情况、护肤美容、皱纹发生时间、发生部位等并对皱纹产生可能相关因素进行室内外组对比分析.结果 246名19～71岁女性,回顾各不同年龄阶段使用防晒措施的比例是:6～11岁年龄段为11%;12～18岁为13.5%;19～29岁为38.5%;30～39岁为39.2%;40～59岁为44%;60～75岁为0.在近5年阶段的为最多达44.1%.出现皱纹与色素斑时间及情况比较:目前无皱纹的占5.7%,目前无色素斑的占21.7%.发现皱纹时间以30～35岁为最多,发现色素斑时间以25～30岁为最多.室内组人群面部皱纹发生的顺序由多到少依次是眶下、外眦、鼻唇沟区域、眉间;室外组皱纹最多出现的依次顺序依次是:外眦、眶下、眉间、鼻唇沟.室内人群皱纹最常发生于鱼尾纹,至少在45岁达100%.而室外人群的皱纹发生普遍早,鱼尾纹至少在30岁就达100%.结论 皱纹和色素斑均为中国女性皮肤老化的主要表现.色素斑出现时间略早于皱纹.女性皮肤光老化的主要表现依次为肤色灰黄、皮肤干燥、粗糙、皮革样外观、显著的红血丝和(或)严重的色素斑、脆性增加等.室内组女性皱纹出现次序和时间都有别于室外组.

Abstract：

Objective To estimate the prevalence and associated factors of facial wrinkling in females.Methods Questionnaires were designed and delivered to collect related data on volunteers. The subjects were divided into outdoor and indoor groups. Wrinkles were classified into 9 grades based on photos taken by SIA0612 image analyzer and quantification analysis via Visioscan VC 98. SPSS 17.0 software was used to assess the associated factors of wrinkling, including sun-protective measures, skin care and cosmetology, onset age and location of wrinkles in these subjects. Results A total of 246 patients aged 19 - 71 years were recruited in this study. Sun-protective measures were applied in 13.5% of the subjects between 12 and 18 years of age,38.5% of those between 19 and 29 years of age, 39.2% of those between 30 and 39 years of age, 44% of those between 40 and 59 years of age, and in none of those between 60 and 75 years of age, 44.1% of all the subjects in the latest 5 years. Wrinkles were absent in 5.7% of the subjects, and pigmentation macules absent in 21.7%. The first development of wrinkles was mainly observed in subjects aged 30 to 35 years, and that of pigmentation macules in those aged 25 to 30 years. The most common locations of facial wrinkles, in order of decreasing frequency, were infraorbital area, lateral angle of eye, nasolabial fold, glabella in the indoor group,lateral angle of eye, infraorbital area, glabella and nasolabial fold in the outdoor group. Fishtail lines seemed to be the commonest wrinkles with an earliest onset among these wrinkles, and showed a prevalence of 100% in subjects aged 45 years or older in the indoor group, and in those aged 30 years or older in the outdoor group.Conclusions Wrinkles and pigmentation macules are dominate manifestations of skin aging in Chinese females. The onset of pigmentation macules is earlier than that of wrinkles. The main manifestations of skin aging in Chinese females, in order of decreasing frequency, are yellow-grey skin, skin dryness, roughness,leather-like appearance, teleangiectasia, and (or) severe pigmentation macules, increase in skin fragility, etc.The order and age of wrinkle appearance are different between indoor and outdoor females.     

Synthesis of glycosaminoglycans and collagen in skin fibroblasts cultured from a patient with lichen myxedematosus

Summary A patient is described with typical skin lesions of lichen myxedematosus and IgG-type lambda paraproteinemia. Fibroblasts cultured from the skin of the patient and from the skin of control persons were used to study glycosaminoglycan and collagen synthesis; the cultures were labelled with ³H-glucosamine and ³H-proline, respectively. Fibroblasts from the patient grew to a cell density which was lower than that of the control fibroblasts. The production of glycosaminoglycans was increased in lichen myxedematosus cultures, so that the ratio of hyaluronic acid to sulphated glucosaminoglycans was higher in the patient's cultures than in control cultures. Collagen production in the patient's cultures was about half of that in control cultures, whereas the ratio of type III to type I collagen was normal.     

The ratio of glycosaminoglycans to collagen in the skin in malignant melanoma

Summary The interaction between glycosaminoglycans and collagen was determined in 24 subjects with malignant melanomas. The analysis indicates that the ratio of hexosamine to collagen was higher in the center of the tumor than in the outer areas. Our findings could result from dysregulation of the biosynthesis of glycosaminoglycanes.Dedicated in gratitude to Prof. J. Kühnau, MD, former director of the Institute of Physiological Chemistry, University of Hamburg on the occasion of his 80th birthday     

Molecular changes during skin aging and wound healing after fractional ablative photothermolysis

Photo‐damaged skin is characterized by major alterations of the extracellular matrix and collagen network, leading to clinically obvious signs of skin aging. UV radiation increases the levels of matrix metalloproteinase (MMP) 1, which initiates the cleavage of fibrillar collagen types I and III. The developing collagen fragments are further degraded by MMPs 2 and 9. Various ablative, non‐ablative, thermal and non‐thermal rejuvenation modalities have been tested for their capacity to reverse epidermal and dermal signs of photo‐ and chronological‐aging. Light and laser therapies are among the most effective treatment options for skin rejuvenation. Conventional laser therapy treats entire surface areas by selective photothermolysis or ablation. Recently, intervention with a fractional ablative laser leads to fast wound healing, and hence, a substantial amount of the target skin area is left untreated. It is not known if the efficacy of a particular ablative skin rejuvenation treatment depends on the extent of microwounding and/or the amount of heat produced. The underlying molecular changes are not fully understood but have been postulated to be induced by time‐dependent changes in heat shock proteins, transforming growth factor β, MMPs, hyaluronic acid synthethases, hyaluronidases and HA, among others.     

A study on the delayed effect of tilapia skin collagen on skin aging for mice and its possible mechanism

Objective

Study the possible mechanism and delayed effect of tilapia skin collagen on skin aging for mice.

Materials and Methods

Kunming (KM) mice were randomly divided into the aging model group, the normal group, the positive control group (vitamin E) and the low, medium, high dose tilapia skin collagen groups (2.0, 4.0, 8.0 mg/g). The normal group was only injected with saline at the back and the neck. The other groups were injected subcutaneously with 5% D-galactose and ultraviolet light jointly to establish the aging model. After modeling, the positive control group was treated with a dose of 10% vitamin E once a day, and the low, medium, high dose tilapia skin collagen group was separately applied 2.0, 4.0, 8.0 mg/g of tilapia skin collagen for 40 days. The changes of skin tissue morphology, water content, hydroxyproline (Hyp) content, and superoxide dismutase (SOD) activity in mice were studied at the day 10, 20, 30, 40, 50.

Results

Compared with the normal group, the skin of mice in the aging model group was thinner, looser, and the skin moisture content, Hyp content, SOD activity were all decreased. For mice of the low, medium, high dose tilapia skin collagen group, the thickness of dermis increased, possessing close arrangement, and the moisture content, Hyp content, SOD activity were up-regulated significantly, which effectively alleviated the aging process of skin. The dose of tilapia skin collagen was directly proportional to the anti-aging effect.

Conclusions

Tilapia skin collagen has an obvious effect on improving skin aging.     

类人胶原蛋白敷料治疗面部脂溢性皮炎疗效观察及对皮肤屏障功能的影响

目的探讨类人胶原蛋白敷料治疗面部脂溢性皮炎的疗效、安全性及其对皮肤屏障功能的影响。方法将20~50岁女性面部脂溢性皮炎患者67例随机入组,试验组患者外用酮康唑乳膏加类人胶原蛋白敷料,对照组患者单独外用酮康唑乳膏,两组患者均用药10 d,观察皮损变化并测定皮肤屏障功能相关指标。结果第2次随访时,试验组症状积分[(1.06±1.06)分]、经皮水分丢失量(transepidermal water loss,TEWL)[(11.99±5.84)g/(m2?h)]均低于对照组[(1.94±1.17)分、(16.17±8.47)g/(m2?h)],角质层含水量(40.20±11.69)高于对照组(34.13±10.86),差异均有统计学意义(P=0.002,0.024,0.033)。两组患者均未出现明显不良反应。结论类人胶原蛋白敷料治疗成年女性面部脂溢性皮炎,能改善皮肤屏障功能,减轻皮损,可以作为面部脂溢性皮炎的一个安全有效的辅助治疗手段。     

D-半乳糖诱导性亚急性衰老大鼠模型皮肤胶原代谢及相关通路分子的表达

目的：明确D-半乳糖诱导的亚急性衰老大鼠皮肤胶原代谢及TGFβ1/smads通道分子的表达。方法：20只大鼠随机分为对照组和衰老组,衰老组大鼠颈背部皮下注射D-半乳糖125 mg/kg?d,连续6周,对照组以同样的方法注射相同剂量的无菌生理盐水。活体皮肤共聚焦显微镜观察两组大鼠皮肤胶原纤维密度的变化。RT-PCR检测TGFβ1、Smad3、 I 型前胶原蛋白、III 型前胶原蛋白及脂质金属蛋白酶抑制剂-1的mRNA水平。结果：衰老组大鼠皮肤胶原纤维密度及TGFβ1、Smad3、 I 型前胶原蛋白、脂质金属蛋白酶抑制剂-1mRNA均低于正常对照组(P<0.05).;脂质金属蛋白酶-1mRNA表达量高于对照组(P<0.05).; III 型前胶原蛋白mRNA表达量在两组间没有差异。结论：D-半乳糖可通过下调TGFβ1/Smads通路分子的表达量抑制I 型前胶原蛋白合成,并通过调节脂质金属蛋白酶-1/脂质金属蛋白酶抑制剂-1促进胶原蛋白降解,使皮肤出现亚急性衰老效应。     

Age and skin structure and function, a quantitative approach (II): protein, glycosaminoglycan, water, and lipid content and structure

BACKGROUND/PURPOSE: The aging process has been studied with fervor recently, given our shifting demographics. As age's effects are so manifest in the skin's appearance, structure, mechanics, and barrier function, it is not surprising that much effort has been made in research to better understand them. Quantitative measurements permitted by bioengineering have allowed us to objectively and precisely study aging skin. These overviews piece together the immense amounts of information that have emerged from recent technological advances in dermatological research in order to develop a unified understanding of the quantitative effects of age on skin. METHODS: We performed a literature search on age-related changes in protein, glycosaminoglycan (GAG), water, and lipid content and structure, searching Pub-med, Em-Base, Science Citation Index, and the UCSF dermatological library's collection of books on the topic of aging skin. RESULTS: Collagen becomes sparser and less soluble in intrinsically aged skin, but is thickened and more soluble in extrinsically aged areas. Elastin is degraded slowly and accumulates damage with intrinsic aging; also, increased synthesis of abnormally structured elastin occurs in photoexposed areas. This leads to an age-related accumulation of aberrant elastoic material, clumped in the papillary dermis. Generally, age leads to increased folding and decreased interaction of proteins with water. Also, despite increased GAGs in aged skin, these are abnormally deposited on the elastoic material and cannot interact properly with water. Hence, in aged skin, water is found in the tetrahedron form, bound to itself rather than other molecules. Lipid content appears to decrease with age, although the proportion of different lipid classes seems to remain fairly constant. CONCLUSION: Much work remains to be carried out to reach a consensus on the effects of age on skin structure and function. Future studies would be benefited by increased standardization of skin sites tested, methodology, and increased sample sizes.     

点阵Er:YAG激光对光老化豚鼠皮肤胶原纤维和弹性纤维的影响

目的 探讨点阵Er:YAG激光照射对紫外线所致豚鼠光老化皮肤胶原纤维和弹性纤维的影响.方法 随机数字表法将60只豚鼠分为无处理组10只和模型组50只,中波紫外线(UVB)和长波紫外线(UVA)照射模型组豚鼠皮肤构建光老化模型,随机选择10只作为光老化模型组,余40只豚鼠分为2周、4周、8周、12周治疗组.点阵Er:YAG激光连续多脉冲照射治疗组豚鼠左侧背部(治疗侧)皮肤,HE染色、Masson染色、Weigert-van Gieson染色和碱水解-分光光度法比较照射后,治疗侧和对照侧皮肤组织学改变、胶原纤维、弹性纤维和羟脯氨酸含量.结果 UVA和UVB的最小红斑量4224 mJ/cm2和504 mJ/cm2隔日照射豚鼠背部皮肤,累积照射UVA 459.36 J/cm2和UVB 54.81 J/cm2,成功获得光老化模型.HE染色显示,治疗组治疗侧皮肤真皮浅层激光刺激区新生的胶原纤维和弹性纤维增加、排列致密.12周组Masson染色胶原面积比值治疗侧(0.70±0.12)较对照侧(0.63±0.08)均有增加,差异有统计学意义(f=1.18,P＜0.05);羟脯氨酸含量治疗侧[(4.73±0.39) mg/g]较对照侧[(3.66±0.85) mg/g]亦有增加,差异有统计学意义(t=3.40,P＜ 0.05).结论 点阵Er:YAG激光连续多脉冲照射可以刺激光老化豚鼠皮肤真皮浅层胶原纤维含量增加,纤细的弹性纤维新生.