Moragas A, García-Bonafé M, Sans M, Torán N, Huguet P, Martín-Plata C
Department of Anatomic Pathology, Hospitals Universitaris Vall d'Hebron, Barcelona, Spain.
Anal Quant Cytol Histol. 1998 Dec;20(6):493-9.
To determine progressive quantitative, directional and textural changes in dermal collagen as a function of age and sex and to estimate their evolutive trend with appropriate regression models.
Ninety-six samples of abdominal skin from autopsy cases were analyzed. The ages ranged from 3.5 months to 86 years. Picro-Sirius-stained slides were examined by polarizing microscopy, and spatial density, directional features and texture of collagen were measured by computerized image analysis. Nonlinear regression models were built to estimate evolutive changes with respect to age. The relationship between spatial orientation of collagen bundles and age was best modeled by linear regression.
The evolutive patterns of dermal thickness and spatial density of collagen bundles correspond to a second-order polynomial model with a progressive increase from childhood to middle age and a relatively sharp decrease after the seventh decade. The evolution of textural pattern of dermal collagen, defined by gradient analysis, depicts a sort of inverted U. Its complexity is maximum in the first year of life, decreases until the period 25-50 years and increases progressively after the sixth decade. The horizontal orientation of collagen bundles with intermingled fascicles oriented in other directions, shown by young individuals, is progressively simplified with aging. In elderly subjects, collagen bundles have a horizontal orientation. No significant sex-related differences were found.
Dermal collagen changes related to aging are apparently independent of sex, at least in abdominal skin, and show characteristic curvilinear evolutive trends defined by decreased dermal thickness in the elderly, decrease in the spatial density of collagen bundles and increase in textural heterogeneity of the dermis. Progressive simplification in the orientation of collagen bundles leading to a predominant horizontal disposition followed a linear trend. These changes could contribute to providing a substantial morphologic basis to age-associated biomechanical alterations in the skin.
确定真皮胶原蛋白随年龄和性别的渐进性定量、方向性和纹理变化，并使用适当的回归模型估计其演变趋势。
分析了96例尸检病例的腹部皮肤样本。年龄范围从3.5个月至86岁。通过偏振显微镜检查天狼星苦味酸染色的玻片，并通过计算机图像分析测量胶原蛋白的空间密度、方向性特征和纹理。建立非线性回归模型以估计随年龄的演变变化。胶原蛋白束的空间取向与年龄之间的关系通过线性回归建模效果最佳。
真皮厚度和胶原蛋白束空间密度的演变模式符合二阶多项式模型，从儿童期到中年逐渐增加，在七十岁以后相对急剧下降。通过梯度分析定义的真皮胶原蛋白纹理模式的演变呈现出一种倒U形。其复杂性在生命的第一年最大，在25至50岁期间下降，在六十岁以后逐渐增加。年轻人中显示的胶原蛋白束水平取向以及其他方向交织的束状结构随着年龄增长逐渐简化。在老年受试者中，胶原蛋白束呈水平取向。未发现明显的性别差异。
与衰老相关的真皮胶原蛋白变化显然与性别无关，至少在腹部皮肤中如此，并且呈现出特征性的曲线演变趋势，表现为老年人真皮厚度减少、胶原蛋白束空间密度降低以及真皮纹理异质性增加。胶原蛋白束取向的逐渐简化导致主要的水平排列遵循线性趋势。这些变化可能有助于为皮肤中与年龄相关的生物力学改变提供实质性的形态学基础。
