Bonner-Weir S
Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Diabetes. 2001 Feb;50 Suppl 1:S20-4. doi: 10.2337/diabetes.50.2007.s20.
The pancreatic beta-cells are responsible for the maintenance of the body's glucose levels within a very narrow range; their population is dynamic and undergoes compensatory changes to maintain euglycemia. The structural parameters that allow mass changes (replication, neogenesis, cell volume changes, and cell death) can now be assessed and have proved to be powerful tools. Changes in one parameter can dramatically affect the beta-cell mass. Unfortunately, conclusions are often drawn on measurements that do not assess beta-cell mass but only relative volumes. Throughout the lifetime of a mammal, low levels of beta-cell replication and apoptosis are balanced and result in a slowly increasing mass. The balance allows gradual replacement of the beta-cell population; thus, beta-cells should be considered a slowly renewed tissue. Two major implications of beta-cell turnover are that 1) at any time, the beta-cells would be at different ages and 2) any limitation on replacement could have dire consequences for glucose homeostasis.
胰腺β细胞负责将机体血糖水平维持在非常狭窄的范围内；其数量是动态变化的，并会发生代偿性改变以维持血糖正常。现在可以评估允许质量变化的结构参数（复制、新生、细胞体积变化和细胞死亡），并且已证明这些参数是强有力的工具。一个参数的变化可能会显著影响β细胞数量。不幸的是，人们常常根据未评估β细胞数量而仅评估相对体积的测量结果得出结论。在哺乳动物的整个生命周期中，低水平的β细胞复制和凋亡保持平衡，导致β细胞数量缓慢增加。这种平衡允许β细胞群体逐渐更新；因此，β细胞应被视为一种更新缓慢的组织。β细胞更新的两个主要影响是：1）在任何时候，β细胞都处于不同的年龄；2）对β细胞替代的任何限制都可能对葡萄糖稳态产生严重后果。
