Learn D B, Moloney S J
Skin Biology Research, Schering-Plough HealthCare Products Inc., Memphis, Tennessee 38151-0001.
Photodermatol Photoimmunol Photomed. 1991 Oct;8(5):195-9.
Dermal mast cell numbers reportedly increase in response to chronic ultraviolet irradiation in both humans and in the HRS/Skh-1 mouse model of human photoaging. It has been hypothesized that these increased numbers of mast cells are responsible, at least in part, for the damage in this chronically irradiated or photoaged skin. However, few actual quantitative data have been reported to support this claim of increased dermal mast cell numbers caused by chronic ultraviolet irradiation. We sought to quantify the numbers of dermal mast cells in the skin of chronic ultraviolet-irradiated and control HRS/Skh-1 hairless mice. Dermal mast cells from irradiated and age-matched control mice were quantified by digital image analysis during a 20-week period of exposure to ultraviolet B (UVB) radiation. During the entire course of irradiation, there was no difference in the numbers of dermal mast cells between the irradiated and nonirradiated age-matched control mice. Visible physical evidence of the effects of chronic UVB irradiation, i.e., skin wrinkling, was evident after 6 weeks of treatment. The numbers of dermal mast cells in unirradiated age-matched NSA (CF-1) haired mice were three- to four-fold lower than those in either ultraviolet-exposed or unexposed HRS/Skh-1 mice. These findings indicate that dermal mast cell numbers in HRS/Skh-1 mice are not increased by chronic exposure to UVB radiation.
据报道，在人类以及人类光老化的HRS/Skh-1小鼠模型中，皮肤肥大细胞数量会因长期紫外线照射而增加。据推测，这些增多的肥大细胞至少在一定程度上导致了长期受照射或光老化皮肤的损伤。然而，几乎没有实际的定量数据来支持长期紫外线照射会导致皮肤肥大细胞数量增加这一说法。我们试图对长期紫外线照射的和对照的HRS/Skh-1无毛小鼠皮肤中的真皮肥大细胞数量进行量化。在20周的紫外线B（UVB）辐射暴露期间，通过数字图像分析对受照射小鼠和年龄匹配的对照小鼠的真皮肥大细胞进行量化。在整个照射过程中，受照射小鼠和未受照射的年龄匹配对照小鼠之间的真皮肥大细胞数量没有差异。在治疗6周后，长期UVB照射的影响，即皮肤起皱，有明显的可见物理证据。未受照射的年龄匹配的NSA（CF-1）有毛小鼠的真皮肥大细胞数量比紫外线照射或未照射的HRS/Skh-1小鼠低三到四倍。这些发现表明，长期暴露于UVB辐射不会增加HRS/Skh-1小鼠的真皮肥大细胞数量。
