年龄和饮食对小鼠造血基质细胞复制能力的影响

INFLUENCE OF AGE AND DIET ON THE REPLICATIVE CAPACITY OF MURINE HEMATOPOIETIC STROMAL CELLS

将两种品系小鼠分成５组，即青年，中年，老年和中、老年的限制热量组。培养各组的骨髓、脾脏成纤维细胞和骨髓纯内皮样细胞。结果在明，两种细胞的大克隆百分数随增龄而下降，限制热量能减轻这种下降（Ｐ＜０．０５），并伴小鼠存活率增加。应用体内Ｂｒｄｕ法测定青、老年鼠骨髓ＣＦＵ－Ｆ和纯内皮样细胞的自杀率，发现限制热量组自杀率明显高于任意进食组。提示限制热量能使老年小鼠造血基质细胞进入周期的潜能增加。

he pathogen-free mice of two different strains including male BDF1 and female BC3were used. Mice of each strain was divided into three groups:Young(4～ 7mons),middle-aged(12～22 mons).and old goup(27～35 mons).The middle-aged and the old groups wereagain divided into two sections:ad libitum(AL)and caloric restriction(CR,60%of totalcaloric intake from 12th week of life).The percentage of large clones(≥5cell doublings)offibroblasts of CFU-F in bone marrow and spleen, the percentage of large clones of endothe-lial-like cells in bone marrow and the suicide rate(percentage of killed cells by UV light after14 days action of Brdu in vivo)of fibroblasts and endothelial-like cells of BDF1 were investi-gated.The resuIts indicated that the percentage of large clones decreased with the age in-crease(P<0.05 ).Caloric restrication alleviated the lowering of replicative capacity of thehemopoietic stromal cells(HSC)of the old mice(P<0. 01) with about 30 percent increase ofmurine survival rate. Suicide rate of CR group is obviously higher than that of AL group(P<0.01).These data suggest that caloric restriction can delay the gradual loss of replicative ca-pacity of HSC of old mice which may be related to extension of murine life span.