[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).


CONCLUSIONS
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.
Kang
F
F
Institute of Ophthalmology, Weifang Medical College, Shandong 261042, China.
Kunyan
K
K
Fischbarg
J
J
D000818:Animals; D020346:Aquaporins / Q000096:biosynthesis*; D002417:Cattle; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D004728:Endothelium, Corneal / Q000166:cytology / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*
D020346:Aquaporins