RESUMEN
BACKGROUND AND PURPOSE: Uveitis is a prevalent intraocular inflammatory disease and one of the most damaging ocular conditions. Pretreatment with melatonin prevented ocular inflammation induced by an intravitreal injection of bacterial LPS in the Syrian hamster. Here, we have assessed the anti-inflammatory effects of melatonin administered after the onset of ocular inflammation. EXPERIMENTAL APPROACH: The eyes of male Syrian hamsters were intravitreally injected with vehicle or LPS. Melatonin was injected i.p. every 24 h, starting 12 or 24 h after the LPS injection. A clinical evaluation (with a score index based on clinical symptoms), the number of infiltrating cells, protein concentration and PGE2 and PGF2α levels in the aqueous humour, as well as retinal NOS activity, lipid peroxidation and TNF-α levels were assessed. Retinal function was assessed by scotopic electroretinography, and light microscopy and immunohistochemistry were used to evaluate the state of the retinal structure. KEY RESULTS: Both treatment regimens with melatonin decreased clinical symptoms, reduced the leakage of cells and proteins, and decreased PG levels in aqueous humour from eyes injected with LPS. In addition, melatonin treatment blocked the decrease in scotopic electroretinogram a- and b-wave amplitude, protected the retinal structure and reduced the increase in NOS activity, lipid peroxidation and TNF-α levels, induced by LPS. CONCLUSIONS AND IMPLICATIONS: These results indicate that treatment with melatonin, starting after the onset of uveitis, attenuated ocular inflammation induced by LPS in the Syrian hamster and support the use of melatonin as a therapeutic resource for uveitis treatment.
Asunto(s)
Antioxidantes/farmacología , Humor Acuoso/efectos de los fármacos , Melatonina/farmacología , Retina/efectos de los fármacos , Uveítis/metabolismo , Animales , Humor Acuoso/metabolismo , Cricetinae , Dinoprost/inmunología , Dinoprost/metabolismo , Dinoprostona/inmunología , Dinoprostona/metabolismo , Modelos Animales de Enfermedad , Electrorretinografía , Inmunohistoquímica , Inyecciones Intravítreas , Peroxidación de Lípido/efectos de los fármacos , Lipopolisacáridos/toxicidad , Masculino , Mesocricetus , Óxido Nítrico Sintasa/efectos de los fármacos , Óxido Nítrico Sintasa/metabolismo , Retina/inmunología , Retina/metabolismo , Factor de Necrosis Tumoral alfa/efectos de los fármacos , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Uveítis/inducido químicamente , Uveítis/inmunologíaRESUMEN
Hemp fiber is obtained from the plant Musa textilis. The cost of preparation of its raw fibers is low. The purpose of this paper was to compare the inflammatory response in the rat muscle tissue originated by both hemp and cotton fibers. Both types of fibers, were implanted in gluteal muscles of Sprague Dawley rats. The rats were sacrificed at 15, 30 and 60 postoperative days. Muscle tissue sections were stained with hematoxilyneosin. The inflammatory response was measured by subtracting the suture surface area from the total granulomatous area. At 15 days, the inflammatory response was more conspicuous for hemp than for cotton fiber (P < 0.05). At 30 and 60 days, responses were similar (P > 0.05). We cannot conclude that the hemp fiber is superior to cotton, nevertheless, they behave the same. Therefore, hemp constitutes an alternative as suture material.