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Updated: Apr 29, 2026
Primed Mycobacterial Uveitis PMU as a Model for Post-Infectious Uveitis
Published on: December 17, 2021
The ocular endothelin system: a novel target for the treatment of endotoxin-induced uveitis with bosentan
Sadullah Keles1, Zekai Halici2, Hasan Tarik Atmaca3
1Department of Ophthalmology, Faculty of Medicine, Ataturk University, Erzurum, Turkey.
Purpose:
We compared the anti-inflammatory effects of bosentan and dexamethasone in endotoxin-induced uveitis (EIU).
Methods:
Endotoxin-induced uveitis was induced by subcutaneous injection of lipopolysaccharide (LPS, 200 μg) in Wistar rats. Rats were divided randomly into 10 groups (n = 6). Bosentan at doses of 50 and 100 mg/kg were administered orally 1 hour before and 12 hours after LPS injection, and dexamethasone was administered by intraperitoneally 30 minutes before and 30 minutes after LPS injection at a dose of 1 mg/kg. Data were collected at two time points for each control and treatment; animals were killed at either 3 or 24 hours after LPS injection. Histopathologic evaluation and aqueous humour measurements of TNF-α level were performed, and endothelin-1 (ET-1), inducible nitric oxide synthase (iNOS), and endothelin receptor A and B (EDNRA and B) expression were analyzed.
Results:
The group treated with 100 mg/kg bosentan at 24 hours displayed significantly milder uveitis and fewer inflammatory cells compared to LPS-injected animals, and there were similar findings in the dexamethasone-treated group at 24 hours. The TNF-α levels in the dexamethasone treatment group were lower than those in the LPS-induced uveitis control group (P < 0.05); however, there was no difference between the dexamethasone and bosentan treatment groups at 3 and 24 hours after LPS administration. Bosentan treatment at doses of 50 and 100 mg/kg significantly decreased iNOS expression compared to LPS-injected animals (P < 0.001). The ET-1 expression was suppressed significantly by bosentan and dexamethasone at 3 and 24 hours after LPS administration (P < 0.001). The EDNRA expression in the bosentan treatment groups was statistically significantly lower than that in the LPS-induced uveitis control group at 3 and 24 hours after LPS administration (P < 0.05).
Conclusions:
Bosentan reduces intraocular inflammation and has similar effects as dexamethasone in a rat model of EIU.
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