Serrat Maria A, Vinyard Christopher J, King Donna
School of Biomedical Sciences, Kent State University, Kent, Ohio, USA.
Connect Tissue Res. 2007;48(1):19-26. doi: 10.1080/03008200601021373.
Growth hormone is known to stimulate connective tissue, but the degree to which it influences skin biomechanical properties is unclear. This study tested the hypothesis that human growth hormone transgene expression changes the material properties and structural composition of adult mouse skin. Fracture toughness and elastic modulus were measured on freshly dissected dorsal skin and fixed samples were analyzed histologically. Transgenics had higher elastic moduli than their sex-matched non transgenic littermates, and male transgenics demonstrated increased fracture toughness. Male transgenics also had thicker skin than controls with a selectively increased dermis. In contrast, female transgenics had thinner skin than controls due to a reduced hypodermis. Biomechanical and histological variables were strongly correlated. Significant sex differences were present in nearly all comparisons indicating a dimorphic response to growth hormone in the skin. These data demonstrate that constant low-level growth hormone expression in marrow differentially affects skin layer thickness and concomitantly alters its biomechanical properties.
已知生长激素可刺激结缔组织，但它对皮肤生物力学特性的影响程度尚不清楚。本研究检验了以下假设：人类生长激素转基因表达会改变成年小鼠皮肤的材料特性和结构组成。对刚解剖的背部皮肤测量断裂韧性和弹性模量，并对固定样本进行组织学分析。转基因小鼠的弹性模量高于与其性别匹配的非转基因同窝小鼠，雄性转基因小鼠的断裂韧性增加。雄性转基因小鼠的皮肤也比对照组厚，真皮选择性增厚。相比之下，雌性转基因小鼠的皮肤比对照组薄，原因是皮下组织减少。生物力学和组织学变量密切相关。几乎所有比较中都存在显著的性别差异，表明皮肤对生长激素有二态反应。这些数据表明，骨髓中持续低水平的生长激素表达会不同程度地影响皮肤层厚度，并随之改变其生物力学特性。
