Presence of specific platelet-activating factor binding sites in the rat retina.
The specificity of the effects of platelet-activating factor (PAF) on the electrophysiology of the retina suggests the existence of specific sites for PAF in this tissue. In this study, we report the presence of tritiated PAF ([3H]PAF) specific binding sites in membrane preparations of the retina of albino rats. The binding of [3H]PAF was saturable, specific, time-dependent and reversible. Scatchard analysis of the data revealed that the high-affinity retinal binding site possessed a Kd of 2.9 +/- 0.4 nM and Bmax of 0.85 +/- 0.16 pmol/mg protein. These values are comparable with those found for the membranous PAF receptor sites in platelets, neutrophils, lung tissue and brain. We have recently reported that PAF dose dependently modulates the b-wave of the electroretinogram (ERG) obtained from the isolated rat retina. The results of the present study suggest that such PAF-induced disturbances of the ERG may be mediated via specific receptors located in the retina.
Thierry
A
A
Laboratoire de Biophysique, Facultés de Médecine, Unité INSERM U71, Clermont-Ferrand, France.
Doly
M
M
Braquet
P
P
Cluzel
J
J
Meyniel
G
G
D000818:Animals; D001381:Azepines / Q000494:pharmacology; D004224:Diterpenes; D046934:Ginkgolides; D066298:In Vitro Techniques; D007783:Lactones / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000378:metabolism; D010980:Platelet Membrane Glycoproteins; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled; D012160:Retina / Q000378:metabolism*; D014227:Triazines / Q000494:pharmacology; D014230:Triazoles
D001381:Azepines; D004224:Diterpenes; D046934:Ginkgolides; D007783:Lactones; D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D014227:Triazines; D014230:Triazoles; C039351:platelet activating factor receptor; C052518:WEB 2086; C045856:ginkgolide B