Korean J Ophthalmol.  2010 Jun;24(3):169-172. 10.3341/kjo.2010.24.3.169.

The Effect of Brimonidine on Transepithelial Resistance in a Human Retinal Pigment Epithelial Cell Line

• Park JH
• Kim SJ
• Yu HG

• KMID: 945988
• DOI: http://doi.org/10.3341/kjo.2010.24.3.169

Abstract

PURPOSE
To investigate the effects of brimonidine, an alpha-2-adrenergic agonist, on barrier function in ARPE-19 cells by measuring transepithelial resistance (TER). METHODS: ARPE-19 cells were cultured into a confluent monolayer on a microporous filter. Brimonidine was added to the apical medium, and the barrier function of the cells was evaluated by measuring TER. A subset of cells was treated under hypoxic conditions, and the TER changes observed upon administration of brimonidine were compared to those observed in cells in normoxic conditions. RESULTS: The ARPE cell membrane reached a peak resistance of 29.1+/-7.97 Omega cm2 after four weeks of culture. The TER of the cells treated under normoxic conditions increased with brimonidine treatment; however, the TER of the cells treated under hypoxic conditions did not change following the administration of brimonidine. CONCLUSIONS: Barrier function in ARPE-19 cells increased with brimonidine treatment. Understanding the exact mechanism of this barrier function change requires further investigation.

Keyword

Adrenergic agonist; Blood-retinal barrier; Brimonidine; Retinal pigment epithelium

MeSH Terms

Adrenergic alpha-Agonists/*pharmacology
Cell Hypoxia/drug effects/physiology
Cell Line
Electric Impedance
Humans
Quinoxalines/*pharmacology
Receptors, Adrenergic, alpha-2/*drug effects
Retinal Pigment Epithelium/*drug effects/*physiology

Figure

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  Fig. 1 Changes of transepithelial resistance (TER) according to the culture periods. The TER was highest at 4 weeks of culture and decreased thereafter.

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  Fig. 2 The effects of brimonidine on transepithelial resistance in polarized ARPE-19 monolayers cultured in normoxic condition. ARPE-19 cells were treated with 10 nM brimonidine and transepithelial resistance (TER) was measured at indicated time points. Data are mean±2SD (n=14). The TER values showed significant increase compared to the pre-treatment values immediately after the exposure to brimonidine and up to 30 minutes. Thereafter, the TER decreased until it returned to its baseline level two hours following brimonidine treatment.

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  Fig. 3 The effects of brimonidine on transepithelial resistance (TER) in polarized ARPE-19 monolayers cultured in hypoxic condition. The TER of the hypoxic ARPE monolayer did not change in the two hours following exposure to brimonidine.

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  Fig. 4 The effects of brimonidine on tranepithelail resistance (TER) in polarized ARPE-19 monolayers cultured in normoxic and hypoxic conditions. The ARPE-19 monolayers treated in the hypoxic chamber showed no increment of TER after the treatment of brimonidine (p=0.038 compared to the baseline value).

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