Ischemic conditioning protects the rat retina in an experimental model of early type 2 diabetes.

Diabetic retinopathy is a leading cause of acquired blindness in adults, mostly affected by type 2 diabetes mellitus (T2DM). We have developed an experimental model of early T2DM in adult rats which mimics some features of human T2DM at its initial stages, and provokes significant retinal alterations. We investigated the effect of ischemic conditioning on retinal changes induced by the moderate metabolic derangement.

Therapeutic efficacy of melatonin in reducing retinal damage in an experimental model of early type 2 diabetes in rats.

Diabetic retinopathy (DR) is a leading cause of acquired blindness in adults, mostly affected by type 2 diabetes mellitus (T2DM). We have developed an experimental model of early T2DM in adult rats which mimics some features of human T2DM at its initial stages and provokes significant retinal alterations. The aim of this work was to analyze the effect of melatonin on retinal changes induced by the moderate metabolic derangement.

Alterations of locomotor activity rhythm and sleep parameters in patients with advanced glaucoma.

The aim of this study was to evaluate the effect of advanced glaucoma on locomotor activity rhythms and related sleep parameters. Nine normal subjects and nine age-matched patients with bilateral advanced primary open-angle glaucoma, >10 yrs since diagnosis, were included in this observational, prospective, case-control study. Patients were required to record the timing and duration of their sleep and daily activities, and wore an actigraph on the wrist of the nondominant arm for 20 d.

Retinal changes in an experimental model of early type 2 diabetes in rats characterized by non-fasting hyperglycemia.

Diabetic retinopathy is a leading cause of acquired blindness in young, but also in elder adults, mostly affected by type 2 diabetes mellitus (T2DM). The aim of this work was to develop an experimental model of early human T2DM in adult rats, and to analyze retinal functional, morphological, and biochemical changes arising during the early stages of the moderate metabolic derangement. For this purpose, animals were divided in four groups: adult male Wistar rats receiving: tap water and citrate buffer i.

Therapeutic benefit of melatonin in experimental feline uveitis.

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.

Effect of ocular hypertension on retinal GABAergic activity.

Glutamate and gamma-aminobutyric acid (GABA) are major excitatory and inhibitory retinal neurotransmitters. The balance between these signals is a key principle of organization at retinal level. Although glutamate-induced excitotoxicity could mediate retinal ganglion cell death in glaucoma, the GABAergic system was not previously examined in this disease.

Effect of ocular hypertension on retinal nitridergic pathway activity.

Purpose: Understanding the mechanisms of neuronal cell death in glaucoma is important for devising new treatments. Excitatory amino acids, excessive Ca(2+) influx, and formation of nitric oxide (NO) via NO synthase (NOS)-1 could be involved in glaucomatous neuropathy. The purpose of the present study was to examine the retinal nitridergic pathway activity in rats exposed to experimentally elevated intraocular pressure.

Effect of glaucoma on the retinal glutamate/glutamine cycle activity.

Glutamate-induced excitotoxicity has been proposed to mediate the death of retinal ganglion cells in glaucoma. The metabolic dependence of glutamatergic neurons upon glia via the glutamate/glutamine cycle to provide the precursor for neurotransmitter glutamate is well established. Thus, the aim of the present work was to study the retinal glutamate/glutamine activity in eyes with hypertension induced by intracameral injections of hyaluronic acid (HA).

Retinal oxidative stress induced by high intraocular pressure.

Glaucoma is an optic neuropathy in which retinal ganglion cells die probably through an apoptotic process. Apoptosis is known to involve free radicals in several systems including the retina. In this context, the aim of the present work was to analyze retinal oxidative damage in rats with glaucoma induced by the chronic injection of hyaluronic acid in the eye anterior chamber.

Involvement of Bax protein in the prevention of glucocorticoid-induced thymocytes apoptosis by melatonin.

The antiapoptotic effect of melatonin has been described in several systems. In this study, the antagonistic effect of the methoxyindole on dexamethasone-induced apoptosis in mouse thymocytes was examined. Melatonin decreased both DNA fragmentation, and the number of annexin V-positive cells incubated in the presence of dexamethasone.