Eggleston T A, Roach W P, Mitchell M A, Smith K, Oler D, Johnson T E
Uniformed Services University of the Health Sciences, Department of Preventive Medicine and Biometrics, Bethesda, MD, USA.
Comp Med. 2000 Aug;50(4):391-7.
The current safety standards for lasers operating in the 1,400- to 2,000-nanometer (nm) wavelength region are based on only a few observations at specific wavelengths. On the basis of experimental results conducted with Yorkshire pigs (Sus scrofa domestica), these standards may not accurately reflect the potential for laser injury when humans are exposed to these wavelengths. It is our belief that one of the damage mechanisms involved in these laser injuries results from energy absorption by skin pigmentation (melanin), and a more highly pigmented animal model, the Yucatan hairless minipig, may be a more suitable subject for laser exposure studies.
Skin specimens were collected from Yorkshire pigs and Yucatan minipigs for histologic examination, and the thickness of the epidermis was measured. Epidermal thickness of human skin also was determined, and a qualitative assessment of the melanin content in the epidermal layers was conducted.
Mean +/- SD thicknesses of the Yucatan minipig flank and dorsal neck epidermis were 68 +/- 34 and 68 +/- 25 microm, respectively. Thicknesses of the Yucatan minipig skin were closely comparable to the thicknesses of human epidermis from the face (68 +/- 26 microm), neck (65 +/- 24 microm) and arms (68 +/- 21 microm). The Yorkshire pig lacks substantial melanin in the epidermis, whereas the skin of the Yucatan minipig is more similar to that of humans.
On the basis of epidermal skin thickness measurements and melanin assessment, the flank and dorsal neck of the Yucatan minipig are better suited to laser injury studies than are the Yorkshire pig models of human skin.
目前针对波长在1400至2000纳米（nm）区域的激光操作的安全标准仅基于特定波长下的少量观察结果。根据对约克夏猪（Sus scrofa domestica）进行的实验结果，这些标准可能无法准确反映人类暴露于这些波长时激光造成损伤的可能性。我们认为，这些激光损伤所涉及的一种损伤机制是皮肤色素沉着（黑色素）吸收能量所致，而色素沉着程度更高的动物模型——尤卡坦无毛小型猪，可能是更适合用于激光照射研究的对象。
从约克夏猪和尤卡坦小型猪身上采集皮肤标本进行组织学检查，并测量表皮厚度。还测定了人类皮肤的表皮厚度，并对表皮层中的黑色素含量进行了定性评估。
尤卡坦小型猪侧腹和颈背部表皮的平均厚度±标准差分别为68±34微米和68±25微米。尤卡坦小型猪皮肤的厚度与人类面部（68±26微米）、颈部（65±24微米）和手臂（68±21微米）的表皮厚度非常接近。约克夏猪的表皮缺乏大量黑色素，而尤卡坦小型猪的皮肤与人类皮肤更为相似。
基于表皮厚度测量和黑色素评估，与人类皮肤的约克夏猪模型相比，尤卡坦小型猪的侧腹和颈背部更适合用于激光损伤研究。
