Objective To detect the expression of melanocortin 1 receptor (MC-1R) and the melanin contents in human skin autografts and the normal skin, to elucide the role of MC-1R in hyperpigmented process of skin autografts. Methods Skin autografts and normal skin samples were obtained from skin graft on neck who need reoperation to release contractures after 1 year of operations. Immunohistochemical technique was performed to detect the expression and distribution of MC-1R in skin autografts(include full thickenss skin autografts, medium thickness skin autografts, and razorthin skin autografts) and normal skin respectively. MassonFontana staining technique was performedto detect the melanin contents in all sorts specimens respectively. Results The expression of MC-1R was located on cell membrane and cytoplasm of melanocyte and keratinocyte in epidermal. The expression of MC-1R in most skin autografts was much ber than that of control normal skins; the thinnerskin autografts were, the more obvious expressions of MC-1R in skin autografts were. The expressions of MC-1R in all sorts of skinautografts were of significant differences compared with that in normal skins(P＜0.01); the expression of MC-1R in normal skin of donor area was no significant differences compared with normal skin around recipient area(P＞0.01). The contents of melanin in skin autografts were increased obviously and there were significantdifferences compared with that in normal skins(P＜0.01); the contents of melanin among all sorts of skin autografts were of significant differences (P＜0.01). The thinner skin autografts were, the more melanin contents in skin autografts. The expression of MC-1R was positively correlated with the contents ofmelanin in epidermis. Conclusion The expression of MC-1R in skin autografts is significantly higher than that in normal skin and is correlated positively with the contents of melanin in skin autografts. Overexpression of MC-1R may play an important role in hyperpigmented process of skin autografts.
Objective To discuss the expression of α-melanocyte-stimulating hormone(α-MSH) mRNA in human medium thickness skin autografts and to investigatethe role of αMSH in hyperpigmented process of skin autografts. Methods The samples were from medium thickness skin autografts on neck of the patients after 1 year of surgery. The size of sample was about 1.0 cm×0.5 cm. RT-PCR technique was performed to detect the expression of α-MSH mRNA in medium thickness skinautografts and normal skin respectively. Masson-Fontana stain technique was performed to detect the contents of melanin in medium thickness skin autografts andnormal skin epidermis respectively. Results The expression ofα-MSH mRNA in medium thickness skin autografts was much ber than that in control normal skin, showing statistically significant difference (P＜0.01). The expression of α-MSH/β2-microglobulin mRNA in normal skin of donor area was no statistically significant differences compared with normal skin around recipient area. The contents of melaninin medium thickness skin autografts epidermis obviously increased when compared with that of control normal skin. The expression of α-MSH mRNA was positive correlated with the contents of melanin in epidermis. Conclusion The above results indicate that the expression of α-MSH increases greater in medium thicknessskin autografts than in cortrol samples and was correlated with the pigmentation of skin autografts. Overexpression of α-MSH may play an important role in hyperpigmented process of skin autografts.