INVESTIGADORES
DORFMAN Damian
congresos y reuniones científicas
Título:
Mechanisms involved in the anti-inflammatory effect of melatonin in experimental uveitis
Autor/es:
SANDE PH; DORFMAN D; FERNANDEZ DC; CHIANELLI MS; SÁENZ DA; ROSENSTEIN RE
Lugar:
Denver
Reunión:
Congreso; ARVO Annual Meeting 2015; 2015
Resumen:
Purpose: Uveitis is a prevalent intraocular
inflammatory disease. We have previously shown that melatonin not only prevents
but also counteracts LPS-induced uveitis in the Syrian hamster. The aim of this
work was to identify the mechanisms involved in the anti-inflammatory effect of
melatonin administered after the onset of ocular inflammation.
Methods: Syrian hamster eyes were intravitreally
injected with vehicle or LPS. Melatonin was intraperitoneally supplied every 24
h, starting 12 h or 24 h post-LPS injection. Prostaglandin (PG) E2 and PGF2α
levels were assessed (radioimmunoassay) in the aqueous humor. Moreover, retinal
nitric oxide synthase (NOS) activity (using 3H-arginine), lipid
peroxidation (thiobarbituric acid reactive substance levels), and TNFα levels (enzyme-linked immunosorbent assay) were examined.
Light microscopy and immunohistochemistry (Müller cell glial fibrillary
acidic protein (GFAP)) were
used to evaluate the retinal structure.
Results: Concomitantly with an improvement of the
clinical score and retinal function (electroretinogram), both treatments with
melatonin significantly decreased PG levels in aqueous humor from eyes injected
with LPS. Moreover, both treatments with melatonin protected the retinal
structure, reduced Müller cell GFAP levels, and the increase in retinal nitric
oxide synthase (NOS) activity, lipid peroxidation, and TNFα levels induced by
LPS.
Conclusions:
These results indicate the involvement of
aqueous humor prostaglandins, and retinal TNFα levels, NOS activity, and
oxidative stress in the attenuation of ocular inflammation induced by LPS, and
further support the use of melatonin as a therapeutic resource for uveitis
treatment.