THERAPEUTIC BENEFIT OF MELATONIN IN EXPERIMENTAL FELINE UVEITIS

DEL SOLE, MARÍA JOSE; SANDE PABLO; DIEGO CARLOS FERNANDEZ; KELLER SARMIENTO, MARIA; ABA, MARCELO; ROSENSTEIN, RUTH E

JOURNAL OF PINEAL RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Copenhagen; Año: 2012 vol. 52 p. 29 - 37

0742-3098

Uveitis is a frequent ophthalmic disorder which constitutes one of the main causes of blindness in domestic cats. The aim of this report was to analyze the effect of melatonin on experimentally-induced uveitis in cats. Bacterial lipopolysaccharide (LPS) was injected intravitreally into one eye from intact cats, while the contralateral eye was injected with vehicle. Melatonin was orally administered every 24 h to a group of 10 cats, from 24 h before until 45 days after intravitreal injections. Eyes were evaluated by means of clinical evaluation, intraocular pressure (IOP), blood-ocular barrier integrity (via measurement of protein concentration and cell content in samples of aqueous humor), electroretinogram, and histological examination of the retinas. In LPS-treated eyes, several clinical signs were observed until day 45 post-injection. The treatment with melatonin significantly decreased clinical signs and prevented the reduction in IOP induced by LPS. In LPS-injected eyes, melatonin significantly preserved the blood-ocular barrier integrity, as shown by a decrease in the number of infiltrating cells and protein concentration in the aqueous humor. Mean amplitudes of scotopic electroretinogram a- and b-waves were significantly reduced in eyes injected with LPS, whereas melatonin significantly prevented the effect of LPS. At 45 days after injection, LPS induced alterations in photoreceptors and at the middle portion of the retina, whereas melatonin preserved the retinal structure. These results indicate that melatonin prevented clinical, biochemical, functional, and histological alterations induced by LPS injection. Thus, melatonin might constitute a useful tool for the treatment of feline uveitis.