Brantley S K, Davidson S F, Das S K
Department of Surgery, University of Mississippi Medical Center, Jackson 39216.
Am J Med Sci. 1991 Aug;302(2):75-81. doi: 10.1097/00000441-199108000-00002.
A dose-related curve of wound tensile strength was derived following exposure to three doses of predominantly UVA (Ultraviolet A) radiation (98.3% between 315 nm and 400 nm, 1.7% less than 315 nm). Forty female hairless guinea pigs were divided into four equal groups: Group 1 (controls); Group 2 (40 J[Joules]/cm2/day); Group 3 (80 J/cm2); and Group 4 (160 J/cm2). Preoperatively, the experimental groups were irradiated on alternate days for 16 weeks. Serial dorsal punch biopsies (4 mm) were taken prior to the initial exposure and subsequently at 2, 4, 8, 12, and 16 weeks and examined histologically and microscopically. Then, standard 6 cm midline dorsal surgical wounds were made and allowed to heal for 21 days. Wounds were excised and wound tensile strength was assessed. Significant decreases (p less than .05) were noted in wound tensile strength of Groups 2, 3, and 4 compared to the controls, with the decrease being directly related to the dose received. Dermal changes were noted in all irradiated groups as early as four weeks after initial UVA/B exposure. Electron microscopy revealed elastosis and disruption of collagen fibers. Prolonged exposure to radiation, predominantly in the UVA range, appears to impede wound healing in a dose-related fashion and elicits elastosis and collagen disruption.
在暴露于三种主要为UVA（紫外线A）辐射剂量（315纳米至400纳米之间占98.3%，小于315纳米的占1.7%）后，得出了伤口抗张强度与剂量相关的曲线。40只雌性无毛豚鼠被平均分为四组：第1组（对照组）；第2组（40焦耳/平方厘米/天）；第3组（80焦耳/平方厘米）；第4组（160焦耳/平方厘米）。术前，实验组每隔一天接受照射，持续16周。在初次照射前以及随后在第2、4、8、12和16周采集连续的背部打孔活检样本（4毫米），并进行组织学和显微镜检查。然后，制作标准的6厘米中线背部手术伤口，使其愈合21天。切除伤口并评估伤口抗张强度。与对照组相比，第2、3和4组的伤口抗张强度显著降低（p小于0.05），且降低程度与接受的剂量直接相关。早在初次UVA/B照射后四周，在所有受照射组中就观察到了皮肤变化。电子显微镜显示有弹性组织变性和胶原纤维破坏。长时间暴露于主要在UVA范围内的辐射，似乎会以剂量相关的方式阻碍伤口愈合，并引发弹性组织变性和胶原破坏。
