Gallar J, Pozo M A, Rebollo I, Belmonte C
Departamento de Fisiología, Facultad de Medicina, Universidad de Alicante, Spain.
Invest Ophthalmol Vis Sci. 1990 Oct;31(10):1968-74.
This study examined whether the depletion of neuropeptides from sensory nerve terminals induced by capsaicin modifies the healing rate of experimental corneal wounds in adult rabbits. Capsaicin (33 or 3.3 mM solutions) was administered topically and/or by a single retrobulbar injection to one eye while the fellow eye, treated with the vehicle, served as a control. After 1-3 weeks of treatment, an epithelial wound was made in the center of the cornea of both eyes with n-heptanol. Migration rates of epithelial cells surrounding the wound and estimated wound closure times were calculated by measuring the reduction in wound size. Combined treatment with 33 mM retrobulbar and 3.3 mM topical capsaicin for 3 weeks induced a significant delay in epithelial migration rates and in wound closure times (P less than 0.05). Topical or retrobulbar capsaicin alone for 3 weeks and combined treatment lasting only 1 week were not sufficient to modify wound healing times. The substance P antagonist, spantide (3 mM), applied topically for 1-3 weeks before or immediately after corneal wounding was also ineffective in changing wound closure rates. These findings suggest that the delayed wound healing observed after prolonged treatment with capsaicin could be due to a sustained depletion of neuropeptides from corneal sensory endings, supporting the hypothesis that trophic effects of sensory nerves on corneal epithelium are, at least in part, mediated by neuropeptides contained in peripheral nerve terminals.
本研究检测了辣椒素诱导感觉神经末梢神经肽耗竭是否会改变成年兔实验性角膜伤口的愈合速度。将辣椒素（33或3.3 mM溶液）局部给药和/或通过球后单次注射给予一只眼睛，而另一只用赋形剂处理的眼睛作为对照。治疗1 - 3周后，用正庚醇在双眼角膜中央造成上皮伤口。通过测量伤口大小的减小来计算伤口周围上皮细胞的迁移率和估计的伤口闭合时间。33 mM球后注射和3.3 mM局部应用辣椒素联合治疗3周导致上皮迁移率和伤口闭合时间显著延迟（P小于0.05）。单独局部或球后应用辣椒素3周以及仅持续1周的联合治疗不足以改变伤口愈合时间。在角膜损伤前或损伤后立即局部应用P物质拮抗剂spantide（3 mM）1 - 3周，对改变伤口闭合率也无效。这些发现表明，长期用辣椒素治疗后观察到的伤口愈合延迟可能是由于角膜感觉末梢神经肽的持续耗竭，支持了感觉神经对角膜上皮的营养作用至少部分由周围神经末梢中所含神经肽介导的假说。
