The timing of α-gustducin expression during cell renewal in rat vallate taste buds
The timing of α-gustducin expression during cell renewal in rat vallate taste buds
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DOI：
10.1093/chemse/23.6.735
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发表时间：
1998-12-01
期刊：
影响因子：
3.5
通讯作者：
Smith, DV
中科院分区：
文献类型：
--
作者：
Cho, YK;Farbman, AI;Smith, DV
G 蛋白亚基 α-味导素在大鼠 vallate 味蕾的光细胞（II 型）亚群中表达，但在暗细胞（I 型）中不表达。胸苷类似物 5-溴-2'-脱氧尿苷 (BrdU) 在细胞周期的 S 期掺入 DNA，可用于确定细胞的起源时间。在这项研究中，31 只大鼠被注射了 BrdU（50 mg/kg 腹膜内），并在 BrdU 给药后的不同时间（从 2.5 到 10.5 天）进行灌注。将变异的乳头包埋在聚酯蜡中，切成4μm的横截面，并用BrdU和α-味导素的抗体进行表征。对切片进行间接免疫荧光或免疫过氧化物酶程序处理。从 21 只大鼠的免疫过氧化物酶材料中，在每个存活时间从 300-800 个味蕾谱中获得 α-味导素和 BrdU 标记的细胞计数；总共检查了 4122 个味蕾特征。 2.5 天时，味蕾内出现对 BrdU 具有免疫反应性的细胞核，并且双标记细胞在 3.5 天时清晰可见；早在 2.5 天就可以看到少量双标记细胞。双标细胞在6.5天达到峰值，到10.5天没有明显下降。标记有 BrdU 但未标记 α-味导素的细胞在 5.5 天时达到峰值，并在 8.5 天时出现显着下降。后者的细胞包括不表达α-味导素的亮细胞和暗细胞，此前已证明暗细胞的寿命比亮细胞短。这些数据表明，α-味导素的表达出现在细胞生命周期的早期，并且这些细胞比许多不表达这种 G 蛋白的细胞寿命更长。
The G protein subunit alpha-gustducin is expressed in a subset of light (Type II) but not in dark (Type I) cells in rat vallate taste buds. The thymidine analogue 5-bromo-2'-deoxyuridine (BrdU) is incorporated into DNA during the S-phase of the cell cycle and can be used to determine the time of origin of a cell. In this study, 31 rats were injected with BrdU (50 mg/kg i.p.) and perfused at various times, from 2.5 to 10.5 days, following BrdU administration. Variate papillae were embedded in polyester wax, cut into 4 mu m transverse sections, and characterized with antibodies to BrdU and alpha-gustducin. Sections were processed for indirect immunofluorescence or with an immunoperoxidase procedure. From immunoperoxidase material on 21 rats, counts of alpha-gustducin- and BrdU-labeled cells were obtained from 300-800 taste bud profiles at each survival time; a total of 4122 taste bud profiles were examined. Cells with nuclei immunoreactive for BrdU occurred within the taste buds at 2.5 days and double-labeled cells were clearly evident at 3.5 days; a small number of double-labeled cells were seen as early as 2.5 days. Double-labeled cells reached a peak at 6.5 days and did not decline significantly by 10.5 days. Cells labeled for BrdU but not alpha-gustducin peaked at 5.5 days and showed a significant decline by 8.5 days. These latter cells included light cells not expressing alpha-gustducin and dark cells, which have previously been shown to have a shorter life span than light cells. These data suggest that expression of alpha-gustducin appears very early in a cell's life span and that these cells are longer lived than many of the cells that do not express this G protein.