D-半乳糖致衰老模型小鼠皮肤衰老的观察

Effect of D-galactose on parameters for skin aging in murine model

目的 观察D 半乳糖连续皮下注射对小鼠皮肤衰老指标的影响。 方法 3月龄KM雌性小鼠 6 0只 ,随机分为空白对照组 (注射生理盐水 )、D 半乳糖低剂量组 (80mg/kg)和D 半乳糖高剂量组 (10 0 0mg/kg) ,连续每日背部皮下注射 4 2天后 ,观察小鼠皮肤中与衰老相关的生化指标及组织病理学变化 ,并用计算机图像分析系统定量分析。 结果 高剂量组小鼠真皮厚度〔(6 2 4 5±4 8 5 ) μm〕较对照组〔(839 3± 5 8 4 ) μm〕显著变薄 (P <0 0 5 ) ,胶原纤维减少 ,排列疏松 ,弹力纤维总面积亦显著减少 (P <0 0 5 ) ;高剂量组皮肤中超氧化物歧化酶 (SOD)活性〔(131 2± 11 5 )U/ml〕、羟脯氨酸含量〔(0 5 7± 0 13) μg/mg〕显著低于对照组的〔(178 1± 2 0 7)U/ml、(0 74± 0 17) μg /mg ,P <0 0 5〕 ,丙二醛 (MDA)含量增加〔(9 4± 1 5 )nmol/ g和 (6 8± 1 5 )nmol/ g ,P <0 0 5〕 ;而低剂量组上述改变则不显著。 结论 每日 10 0 0mg/kgD 半乳糖连续皮下注射 4 2天 ,可导致小鼠皮肤的明显衰老 ,为抗皮肤衰老研究提供一个简便、稳定的实验模型。

Objective To investigate parameter changes for skin aging in murine model induced by D-galactose. Methods Sixty 3-month-old female mice were randomly divided into three groups: normal control group,low dose (80 mg/kg)and high dose (1000 mg/kg) D-galactose groups. After subcutaneous administration for 6 weeks, the aging models were established. Then, histochemical standards relating to aging were measured and morphologic alterations of surplus dorsal skin were observed under microscope and analyzed. Results In contrast with the control group, high dose D-galactose group showed that the thickness of dermis (624.5 ±48.5) μm was significantly reduced (P<0.05), and the content of elastic fibers was decreased (P<0.05) and accumulated and tangled. The activity of SOD (131.2±11.5)U/ml and content of hydroproline (0.57±0.13)μg/mg were statistically decreased, whereas the content of malondialdehyde (MDA) was remarkably increased. However, low dose group was not significantly different from the normal control group. Conclusions Fourty-two-day administration of D-galactose (1000 mg/kg, sc) to the female mouse can induce skin aging remarkably. It is a simple and stable method to study skin aging.