β内啡肽与μ型-阿片受体在深Ⅱ度烫伤大鼠创面愈合过程中的表达

Expression of β-endorphin and μ-opioid receptor during wound healing process in rat with deep partial-thickness scald

目的观察β内啡肽和μ型-阿片受体（MOR）在深Ⅱ度烫伤大鼠创面愈合过程中的表达。方法将36只Wistar大鼠随机分为对照组（6只）、烫伤组（30只）。烫伤组大鼠被造成5％TBSA深Ⅱ度烫伤，对照组仅模拟烫伤。于伤后即刻及伤后3、7、14、21d取创面组织，采用免疫荧光标记法检测B内啡肽和MOR的表达情况。结果对照组大鼠皮肤组织内β内啡肽和MOR主要分布于表皮、真皮交界的周围神经纤维、表皮的角质形成细胞、真皮的成纤维细胞中，强度较弱。伤后3d，烫伤组B内啡肽表达达峰值（196±16，P＜0．01），在皮肤全层均有表达；MOR集中表达在基底层和基底上的角质形成细胞。伤后7、14d烫伤组B内啡肽仍大量表达。伤后7d，烫伤组MOR的表达进一步增强，胶原排列紊乱；14d时部分创面再上皮化，MOR表达达高峰（306±23，P＜0．01）。伤后21d，烫伤组创面完全再上皮化，周围神经末梢接近并抵达表皮、真皮交界，胶原排列较整齐，β内啡肽的表达（31±24）与对照组（30±18）接近；但MOR的表达（56±16）仍然高于对照组（28±15）。结论烫伤后β内啡肽和MOR的表达具有一定的时效性，这种变化可能影响了创面愈合。

Objective To observe the expression of β-endorphin and μ-opioid receptor （MOR） during wound healing process in rat with deep partial-thickness scald. Methods Thirty-six Wistar rats were randomly divided into control（n = 6, without treatment） , and scald （n = 30, with 5% TBSA deep-partial thickness scald） groups. Skin specimens from wound were harvested immediately after scald and on 3, 7, 14, 21 post-scald days（PSD） for the determination of β-endorphin and MOR expression with immunofluorescent staining. Results β-endorphin and MOR were mainly distributed in nerve terminal at the border of dermis and epidermis , keratinocyte in some epidermis , in the fibroblast in dermis , with a weak expression . The expression of β-endorphin peaked in whole layer of skin on 3 PSD （ 196 ± 16, P 〈 0.01 ） ,while that of MOR was concentrated in keratinocytes in the basal layer and the basement membrane. The expression of MOR was strengthened on 7 PSD with disarrangement of collagen , and it peaked on 14 PSD（306 ± 23, P 〈 0.01） with epithelization in some wounds. There was still strong expression of β-endorphin on 7 and 14 PSD. Complete epithelization was observed in scald group on 21 PSD, with nerve terminal approaching the boundary between the dermis and epidermis, and collagen began to arrange in good order. The expression of β-endorphin in scald group （31 ±24）was similar to that in control group（30 ± 18） on 21 PSD, but the expression of MOR （56 ± 16） was still higher than that in control group （28 ± 15 ）. Conclusion The expression of MOR and β-endorphin exhibits chronobiological nature during the process of wound healing, which may exert certain influence in wound healing.