Prostaglandin-Independent Inhibition of Ocular Vascular Permeability by a Platelet-Activating Factor Antagonist

Prevention of Chloroquine-lnduced Electroretinographic Damage by a New Platelet-Activating Factor Antagonist, BN 50730

“…All these effects are totally inhibited by specific PAF antagonists such as BN 52021 [14], The mechanism by which BN 50730 passes across the blood-retinal barrier is not known, but it is clear that pretreatment with the PAF antagonist abolished the chloroquine-induced ERG impairments. We suggest that pretreatment by BN 50730 could be nec essary to optimize the level of this drug within the retina.…”

Intravitreally injected platelet activating factor induces retinitis in experimental animals

“…The properties of PAF include the ability to attract neutrophils (28), to activate leukocytes (1), and to increase vascular permeability (2). Previous studies with specific inhibitors have implicated PAF in anterior uveitis (5)(6)(7)11), but our previous study based on anterior segment biomicroscopy failed to show inflammatory effects from direct intraocular injection. The studies which we now report have initially utilized a derivative of PAF which is relatively resistant to degradation.…”

“…Evidence strongly suggests that PAF may play a role in ocular inflammation (5)(6)(7)(8)(9)(10)(11). We and others have previously noted that a platelet activating factor antagonist is capable of reducing anterior segment inflammation induced by endotoxin (5), an Arthus reaction (7), tumor necrosis factor (11), or interleukin-1 (6). Furthermore, the mechanism of this inhibition appears to be independent of prostaglandin synthesis such that the PAF antagonist is synergistic with steroidal or non-steroidal anti-inflammatory drugs (5,6).…”

“…We and others have previously noted that a platelet activating factor antagonist is capable of reducing anterior segment inflammation induced by endotoxin (5), an Arthus reaction (7), tumor necrosis factor (11), or interleukin-1 (6). Furthermore, the mechanism of this inhibition appears to be independent of prostaglandin synthesis such that the PAF antagonist is synergistic with steroidal or non-steroidal anti-inflammatory drugs (5,6). In addition, we have recently reported that PAF can be detected in ocular tissue obtained from inflamed rabbit eyes (10).…”

Pharmacokinetic Analysis of Platelet-Activating Factor in the Tears of Guinea Pigs with Allergic Conjunctivitis

“…2 In addition to playing a role in platelet activation, PAF is a highly potent phospholipid mediator that can induce a number of inflammatory responses. 1,3 PAF has been shown to act as a potent chemotactic factor for macrophages, eosinophils, and polymorphonuclear leukocytes 4,5 and to increase vascular permeability. 6 Therefore, PAF is considered an important mediator of inflammation.…”