培养牛角膜上皮细胞水通道蛋白功能的表达

目的 研究培养牛角膜上皮细胞水渗透力（ｗａｔｅｒ ｐｅｒｍｅａｂｉｌｉｔｙ,Ｐｆ）及水通道蛋白（ａｐｕａｐｏｒｉｎｓ,ＡＱＰｓ）的存在。方法 应用激光散射法（ｌａｓｅｒ ｌｉｇｈｔ ｓｃａｔｔｅｒｉｎｇ ｓｙｓｔｅｍ）,测定培养牛角膜上皮细胞自参状态快速转为低渗时体积的改变,并 计算Ｐｆ值：自该细胞提取ｍＲＮＡ注入爪蟾卵。测定卵细胞Ｐｆ值改变。结果 激光散射法测定培养牛角膜上皮细胞Ｐｆ值为７２ｕｍ

Cultured bovine corneal epithelial cells express functional water channel

OBJECTIVE: To investigate the water permeability (P(f)) of the cultured bovine corneal epithelial cells (CBCEC) and whether aquaporins (AQPs) were present. METHODS: Laser light-scattering system was used to determine the volume change of CBCEC from isotonic status rapidly transferred to hypotonic one, and the P(f) value was calculated. Messenger RNA obtained from CBCEC was injected into Xenopus laevis oocytes. After four days, the P(f) was determined by monitoring volume changes of oocytes upon hypoosmotic challenge (180 mOsm/L changed to 15 mOsm/L). RESULTS: CBCEC challenged with 10% hypoosmotic solution at 37 degrees C swelled rapidly; the cellular P(f) was 72 microm/s. In the oocytes injected with mRNA from CBCEC, the P(f) increased to 76 microm/s. This increase was inhibited (by 89%) by 0.3 mmol/L HgCl(2). CONCLUSION: Our results suggest that CBCEC express a typical mercurial-sensitive functional water channel in good numbers, judging from the comparatively high P(f) we measured. These begin to reopen the question of the presence and extent of an epithelial role in control of corneal hydration.