Higuchi Yutaka, Nakamura Hideo, Kawasaki Masaru, Takahashi Sugata
Department of Otolaryngology, Niigata University School of Medicine, Asahi-machi 1, Niigata 951-8510, Japan.
Eur Arch Otorhinolaryngol. 2005 Jan;262(1):64-8. doi: 10.1007/s00405-003-0667-y. Epub 2004 Jan 20.
The dynamics of precursor cells in the olfactory epithelium of juvenile and adult guinea pigs were examined by immunohistochemical double staining using bromodeoxyuridine (BrdU), the neural cell adhesion molecule (N-CAM) and the protein gene product 9.5 (PGP9.5). Expression of apoptotic cells in the olfactory epithelium with the use of the TdT-mediated dUTP biotin nick end labeling (TUNEL) method was also observed. BrdU was given to healthy guinea pigs at the ages of 2 weeks and 6 months old. Tissue specimens were serially collected 1 h to 28 days after administration. BrdU-labeled cells were seen above the basal cell layer after 1 h and migrated to the middle layer of the olfactory epithelium, after 1 day in juveniles and 5 days in adults with expression of N-CAM. PGP9.5 was observed in BrdU-labeled cells after 5 days in juvenile guinea pigs and 7 days in adult. At 14 days after administration, BrdU-labeled cells in the epithelium appeared to decrease. However, a few of these cells were recognized above the basal cell layer after 28 days. The number and location of TUNEL-positive cells did not significantly differ between the juvenile and adult olfactory epithelium. Therefore, we conclude that the division speed from stem cells in juveniles is faster than that in adults, and apoptosis is unaffected by aging in the normal olfactory epithelium.
采用溴脱氧尿苷（BrdU）、神经细胞黏附分子（N-CAM）和蛋白基因产物9.5（PGP9.5）免疫组化双重染色法，检测幼年和成年豚鼠嗅上皮中前体细胞的动态变化。还采用TdT介导的dUTP生物素缺口末端标记法（TUNEL）观察嗅上皮中凋亡细胞的表达。给2周龄和6月龄的健康豚鼠注射BrdU。给药后1小时至28天连续采集组织标本。给药1小时后，在基底细胞层上方可见BrdU标记的细胞，在幼年豚鼠中1天后、成年豚鼠中5天后，这些细胞迁移至嗅上皮中层并表达N-CAM。在幼年豚鼠中5天后、成年豚鼠中7天后，在BrdU标记的细胞中观察到PGP9.5。给药14天后，上皮中BrdU标记的细胞数量似乎减少。然而，28天后在基底细胞层上方仍可识别出少数此类细胞。幼年和成年嗅上皮中TUNEL阳性细胞的数量和位置无显著差异。因此，我们得出结论，幼年干细胞的分裂速度比成年干细胞快，且正常嗅上皮中的细胞凋亡不受衰老影响。
