【摘要】 目的研究烟酰胺对长波紫外线(UVA)致人皮肤黑素细胞增殖的干预作用。方法观察UVA(365nm)0.2cm2照射人皮肤黑素细胞后立即和照射后48h给予不同剂量烟酰胺后的细胞增殖率、细胞内钙离子浓度和Na+-K+、Ca2+-ATP酶活力。结果UVA照射黑素细胞后给予1.000mg/ml烟酰胺,24h即出现抑制黑素细胞增殖的作用,至48h时作用更为明显,自0.125mg/ml组就出现明显的抑制作用;烟酰胺1.25mg/ml可使黑素细胞内钙离子浓度增高;0.250mg/ml可使黑素细胞内Na+-K+、Ca2+-ATP酶活力增高,差异有统计学意义(P<0.05)。经UVA照射后立即给予不同浓度烟酰胺时,细胞内钙离子浓度和Na+-K+、Ca2+-ATP酶活力差异均无统计学意义(P>0.05)。结论UVA照射黑素细胞后即给予烟酰胺对经UVA照射后的保护作用较照射后经过一段时间再给予的作用效果明显。通过影响Ca2+及细胞内钙泵的活性很可能是烟酰胺干预黑素细胞增殖的途径之一。更多还原

【Abstract】 Objective To investigate the interference effect of nicotinamide on UVA-induced cell proliferation in human skin melanocyte. Methods To apply the optimum UVA dose expected to cause cell proliferation:0.2 cm2,nicotinamide was added after the 0.2 cm2 UVA exposure immediately or 48 h later,then the rate of cell proliferation,calcium concentration and the activities of Na+-K+,Ca~2+ -ATP enzymes of melanocytes were measured respectively. Results After treatment with 1.000 mg/ml nicotinamide following UVA exposure,the rate of cell proliferation was decreased significantly 24 hours later.Treatment with 0.125 mg/ml nicotinamide 48 hours after UVA exposure also significantly inhibited the cell proliferation;1.25 mg/ml nicotinamide increased calcium concentration in cells;0.250 mg/ml nicotinamide increased the activities of Na+-K+,Ca~2+ -ATP enzymes in melanocytes(P<0.05). Conclusion Nicotinamide has more obvious effect on inhibiting melanocyte’s proliferation if added immediately following UVA exposure.Our discovery indicated that nicotinamide may affect the melanocyte through modulating the calcium concentration.It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.更多还原