B-CELL SIZE INFLUENCES GLUCOSE-STIMULATED INSULIN-SECRETION
B-CELL SIZE INFLUENCES GLUCOSE-STIMULATED INSULIN-SECRETION
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DOI：
10.1152/ajpcell.1993.265.2.c358
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发表时间：
1993-08-01
影响因子：
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通讯作者：
MEDA, P
中科院分区：
文献类型：
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作者：
GIORDANO, E;CIRULLI, V;MEDA, P
为了确定是否异质性B细胞对葡萄糖的反应与这种糖的不同代谢处理有关，我们比较了大鼠B细胞对葡萄糖刺激的氧化还原反应不同。为此，将暴露于16.7mM葡萄糖15分钟后显示出增加的NAD（P）H自体荧光的B细胞群体从在非常相同的条件下未能显示出基础NADP（H）自体荧光的可检测变化的B细胞群体中分选出来。通过反向溶血空斑试验评价这两个人群（分别称为高和低NAD（P）H）的胰岛素分泌。在用16.7mM葡萄糖刺激30分钟后，两个群体都包含分泌B细胞和不释放可检测量的胰岛素的B细胞。然而，高NAD（P）H人群中分泌B细胞的百分比和总胰岛素输出量（77.9 +/- 6.5%和141.7 +/- 27.4 mum 2 × 10（3））高于低NAD（P）H人群（58.7 +/- 6%和92.7 +/- 20.5 mum 2 × 10（3））（P < 0.01-0.02）。高NAD（P）H群体还包含B细胞，其平均具有比低NAD（P）H群体的B细胞（118.6 +/-1.5 mum 2）更大（P < 0.001）的轮廓面积（142.9 +/-2.3 mum 2）。当比较相似大小的细胞时，葡萄糖诱导的胰岛素分泌在高和低NAD（P）H组中相似，并且在两个群体中作为B细胞大小的函数相似地增加。方差分析显示，胰岛素分泌受B细胞大小的影响（P < 0.005），而不受其NAD（P）H水平的影响。大小也影响B细胞的蛋白质生物合成。这些数据表明，B细胞的分泌和生物合成异质性与它们的大小差异有关，而不是与它们在葡萄糖存在下激活代谢的能力差异有关。
To determine whether the heterogeneous B-cell response to glucose is related to a different metabolic handling of this sugar, we have compared rat B-cells differing in their redox response to glucose stimulation. To this end, a population of B-cells showing increased NAD(P)H autofluorescence after a 15-min exposure to 16.7 mM glucose was sorted from a population of B-cells that, under the very same conditions, failed to show detectable changes in basal NADP(H) autofluorescence. Insulin secretion was evaluated by a reverse hemolytic plaque assay in these two populations, referred to as high and low NAD(P)H, respectively. After a 30-min stimulation by 16.7 mM glucose, both populations comprised secreting B-cells and B-cells that did not release detectable amounts of insulin. However, the percentage of secreting B-cells and total insulin output were larger (P < 0.01-0.02) in the high- (77.9 +/- 6.5% and 141.7 +/- 27.4 mum2 x 10(3)) than in the low-NAD(P)H population (58.7 +/- 6% and 92.7 +/- 20.5 mum2 X 10(3)). The high-NAD(P)H population also comprised B-cells that, on average, had a larger (P < 0.001) profile area (142.9 +/- 2.3 mum2) than the B-cells of the low-NAD(P)H population (118.6 +/- 1.5 mum2). Glucose-induced insulin secretion was similar in the high- and low-NAD(P)H group when cells of similar sizes were compared and increased similarly in the two populations as a function of B-cell size. Analysis of variance revealed that insulin secretion was influenced (P < 0.005) by the size of B-cells and not by their NAD(P)H level. Size also influenced the protein biosynthesis of B-cells. These data show that the secretory and biosynthetic heterogeneity of B-cells is related to differences in their size rather than in their differential ability to activate their metabolism in the presence of glucose.