Abstract
Abstract: :
Purpose: To investigate whether cultured bovine corneal endothelial cells express the glucocorticoid receptor (GR) and to assess the influence of dexamethasone (DEX) on the Na+-K+-ATPase activity in these cells. Methods: Immunocytochemical staining, reverse transcription-polymerase chain reaction (RT-PCR) and Westerning blotting were performed to investigate the existence of glucocorticoid receptor in primary culture of bovine corneal endothelial cells. Primary culture of bovine corneal endothelial cells were isolated, plated for 24 h, and exposed to 10-4 to 10-9 M dexamethasone. These cells were harvested at 0, 3, 6, 12, and 24 h after dexamethasone exposure for determination of Na-K-ATPase activity. RU38486 (GR antagonist) was used to confirm the effect of DEX on the cells. Results: RT-PCR, immunocytochemistry and Western blotting demonstrated the expression of GR (mRNA and protein) in cultured bovine corneal endothelial cells. The Na-K-ATPase activity increased in primary culture of bovine corneal endothelial cells 6, 12, and 24 h after dexamethasone exposure (concentrations from 10-9 to 10-5 M), with a maximum effect at 10-7 M (P < 0.005). Dexamethasone's effect on Na-K-ATPase activity was inhibited by RU38486. (P < 0.05). Conclusions: These results indicate that cultured bovine corneal endothelial cells express the GR. Dexamethasone regulates Na-K-ATPase in bovine corneal endothelial cells with concentrations from 10-9 to 10-5 M.
Keywords: cornea: endothelium • corticosteroids • NaK ATPase