Gomi F, Utsumi H, Hamada A, Matsuo M
Tokyo Metropolitan Institute of Gerontology, Japan.
Life Sci. 1993;52(25):2027-33. doi: 10.1016/0024-3205(93)90687-x.
After the nitroxyl radical 3-carbamoyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl (carbamoylPROXYL) was intraperitoneally administered to mice, the time courses of changes in the intensity of signals in L-band electron spin resonance spectra from their brains were measured. The spin clearance rate of old, ad libitum-fed mice was lower than that of young, ad libitum-fed mice. The rate of old, food-restricted mice was significantly higher than that of old, ad libitum-fed mice and was comparable to that of young, ad libitum-fed mice. The spin clearance was found to be due to the one-electron reduction of the nitroxyl radical, because a decreased spin intensity of it in serum was restored to the original level by potassium hexacyanoferrate (III) oxidation in vitro. These results suggest that reducing capacity in the cardiovascular system of mice is decreased with advancing age, and that food restriction prevents an age-dependent decrease in the reducing capacity.
将硝酰自由基3-氨基甲酰基-2,2,5,5-四甲基-1-吡咯烷基氧基（氨基甲酰基PROXYL）腹腔注射给小鼠后，测量了它们大脑L波段电子自旋共振光谱中信号强度的变化时间进程。自由进食的老年小鼠的自旋清除率低于自由进食的年轻小鼠。食物受限的老年小鼠的清除率显著高于自由进食的老年小鼠，且与自由进食的年轻小鼠相当。发现自旋清除是由于硝酰自由基的单电子还原，因为体外六氰合铁酸钾（III）氧化可将其血清中降低的自旋强度恢复到原始水平。这些结果表明，小鼠心血管系统的还原能力随着年龄的增长而下降，并且食物限制可防止还原能力随年龄的下降。
