Pyruvate ophthalmic drops: anticataract effect in naphthalene- treated albino rats and aqueous humor concentration in albino rabbits

This study was performed to determine the cataract-preventive effect of pyruvate ophthalmic drops in naphthalene-treated albino rats and the in vivo corneal pyruvate penetration in albino rabbits. The anticataract effect of topical pyruvate was evaluated in comparison with placebo eye drops in albino rats treated with naphthalene for three weeks. The levels of reduced glutathione [GSH], malondialdehyde [MDA] and insoluble protein fraction were measured in rat lenses of both groups. Also, pyruvate level was measured in aqueous humor after single ocular instillation in albino rabbits. Reduced glutathione, malondialdehyde and insoluble lens protein fraction were maintained in pyruvate-treated group, while they were significantly changed from normal values in the placebo-treated group. In ocular kinetic studies in rabbits, basal aqueous pyruvate level was 500 +/- 40 microM and increased to 1400 +/- 100 microM after ophthalmic application of a single drop of pyruvate 10% solution. Maintenance of GSH, MDA and insoluble protein fraction indicate the anticataract effect of topical pyruvate drops in naphthalene-treated rats. Also, significant concentration of pyruvate achieved in aqueous humor indicate good corneal penetrability of pyruvate and high ocular bioavailability

Effect of intravenous anesthetics on endothelium-dependent vasodilatation in intact rats

In-vitro studies had shown that ketamine, thiopental and propofol attenuated endothelium-dependent vasodilatation in different species. In this study, the effect of intravenous anesthetics on endothelium-dependent and - independent vasodilatation was examined in intact rats. The effect of acetylcholine and sodium nitroprusside on mean arterial pressure [MAP] was examined in conscious and ketamine, thiopental, propofol and urethane anesthetized rats. MAP was significantly higher in ketamine-anesthetized rats than in conscious rats. There was no significant change in MAP in other anesthetized groups. Also, acetylcholine and sodium nitroprusside induced dose-dependent decrease in MAP in all groups. Ketamine and thiopental potentiated the vasodepressor effect of both acetylcholine and sodium nitroprusside in comparison to the conscious group. Propofol did not have any significant effect on the vasodepressor response to both acetylcholine and sodium nitroprusside. Urethane potentiated the effect of acetylcholine but not that of sodium nitroprusside induced vasodilatation. Ketamine and thiopental, but not propofol, potentiated both endothelium-dependent and independent vasodilatation in intact rats