Abstract: Objective To observe the changes of morphology and biochemical parameters in rats with D-galactose-induced skin ageing.Methods Twenty-six female and male rats were randomly divided into 2 groups.D-galactose group rats were injected subcutaneously with 120 mg·kg^-1·d^-1 of D-galactose everyday,whereas the control group with normal saline.The rats were sacrificed on days 100.The ageing-related biochemical parameters were detected in the blood and skin,and the cutaneous histopathology was observed.Epidermal thickness and area of elastic fibers were determined quantitatively with imaging analysis system.Results Epidermal thickness and content of elastic fibers were significantly lower in D-galactose group than those in the control group.The loose arrangement of collagen and elastic fibers was evident in D-galactose group.These features of the rats in D-galactose group were similar to those in the ageing skin of human beings.Compared with the control group,the levels of hydroxyproline decreased and malondialdehyde (MDA) increased in the skin of the D-galactose group.The activity of glutathione peroxidase (GSH-PX) and catalase (CAT) in the whole blood and that of superoxide dismutase (SOD) in erythrocytes were remarkably reduced in the D-galactose group as compared to the control group.Conclusions The rat models with skin ageing are established by subcutaneous injection of 120 mg·kg^-1·d^-1 of D-galactose once daily for 100 days.The changes of morphologic and biochemical parameters in these models are analogous to those in human skin ageing.

Key words: Skin aging, Galactose