Ward R Scott, Tuckett Robert P, English Kathleen B, Johansson Olle, Saffle Jeffrey R
Department of Physical Therapy, University of Utah, Salt Lake City, Utah, USA.
J Surg Res. 2004 May 15;118(2):154-60. doi: 10.1016/S0022-4804(03)00350-0.
Our knowledge of afferent nerve fiber reinnervation of grafted skin following third-degree burn is limited by a lack of quantitative histological and psychophysical assessment from the same cutaneous area. The current study compares fiber profile and functional recovery measurements in injured and control skin from the same subject.
Nerve regeneration and modality-specific sensory thresholds were compared using immunocytochemical labeling with protein gene product 9.5 antibody to stain all axons and anti-substance P to label substance P axons (which are predominantly unmyelinated), as well as computerized instrumentation to obtain psychophysical estimates.
Compared to control skin, threshold measures of pinprick (P < 0.001), warming (P < 0.001), touch (P < 0.001), and vibration (P < 0.01) were significantly elevated in burn-graft skin and correlated with histological analysis of skin biopsies obtained from the same site. Immunohistochemical staining of all axons innervating the dermis and epidermis revealed a significant reduction in burn-graft relative to control skin (54% decrease, P < 0.0001). In contrast, the incidence of substance P nerve fibers was significantly elevated in burn-graft (177% increase, P < 0.05) and appeared to correlate with patient reports of pruritus and pain.
Observations support the hypothesis that sensory regeneration is fiber-size-dependent in burn-graft skin. The findings that substance P fiber growth increased while total fiber count decreased and that thermal threshold showed the greatest degree of functional recovery suggest that unmyelinated neurons have the greater ability to transverse scar tissue and reinnervate grafted skin following third-degree burn injury.
由于缺乏对同一皮肤区域进行定量组织学和心理物理学评估，我们对三度烧伤后移植皮肤的传入神经纤维再支配的了解有限。本研究比较了同一受试者受伤皮肤和对照皮肤的纤维分布及功能恢复情况。
使用蛋白质基因产物9.5抗体进行免疫细胞化学标记以染色所有轴突，用抗P物质抗体标记P物质轴突（主要是无髓鞘的），比较神经再生和特定模态的感觉阈值，同时使用计算机仪器获得心理物理学估计值。
与对照皮肤相比，烧伤移植皮肤的针刺觉（P < 0.001）、温觉（P < 0.001）、触觉（P < 0.001）和振动觉（P < 0.01）阈值显著升高，且与从同一部位获取的皮肤活检组织学分析相关。对支配真皮和表皮的所有轴突进行免疫组织化学染色显示，烧伤移植皮肤相对于对照皮肤显著减少（减少54%，P < 0.0001）。相比之下，烧伤移植皮肤中P物质神经纤维的发生率显著升高（增加177%，P < 0.05），且似乎与患者的瘙痒和疼痛报告相关。
观察结果支持以下假设，即烧伤移植皮肤中的感觉再生取决于纤维大小。P物质纤维生长增加而总纤维数量减少以及热阈值显示出最大程度的功能恢复，这些发现表明无髓鞘神经元在三度烧伤损伤后具有更强的穿越瘢痕组织并重新支配移植皮肤的能力。
