5-S-GAD, a novel radical scavenging compound, prevents lens opacity development.

The ability of N-beta-alanyl-5-S-glutathionyl-3,4-dihydroxyphenylalanine (5-S-GAD)-a novel catechol derivative isolated from an insect as an antibacterial substance-to scavenge free radicals and prevent cataract progression was examined. 5-S-GAD scavenged 1,1-diphenylpicrylhydrazyl (DPPH) and superoxide anions (O(2)(*)(-)), and inhibited lipid peroxidation. It also significantly inhibited the onset of glucocorticoid-induced lens opacification in chick embryos.

5-HT(2) receptor-mediated phosphoinositide hydrolysis in bovine ciliary epithelium.

The serotonin 2 (5-HT(2)) receptor antagonists, MCI-9042 (Anplag) and ketanserin, have been shown to lower intraocular pressure in rabbits (1) and humans (2). The mechanism of action of these drugs has not been determined, but it is hypothesized that 5-HT(2) receptors, and possibly alpha-adrenergic receptors, (3) may regulate in part aqueous humor production via an intracellular signal transduction pathway in the ciliary body. We therefore examined whether 5-HT(2) receptors were coupled to phosphoinositide hydrolysis in an organ culture system of isolated bovine ciliary epithelium.

Effect of MCI-9042, a 5-HT2 receptor antagonist, on retinal ganglion cell death and retinal ischemia.

The neuroprotective effect of MCI-9042 (Mitsubishi Pharma Corporation) was investigated on glutamate-induced retinal ganglion cell (RGC) death in vitro and on rat retinal ischemia in vivo. RGCs were purified from retinal cells isolated from 6-day-old Wistar rats and cultured in serum-free media. After application of 25 microM glutamate, the viability of RGCs treated with or without several serotonin 2 (5-HT(2)) receptor antagonists: MCI-9042, M-1 (a major metabolite of MCI-9042), ketanserin, and LY-53857; was evaluated by calcein-acetoxymethyl ester staining.