Autoradiographic distribution of peripheral benzodiazepine receptors in the retina of the albino rabbit, Lepus cunicula

The distribution of peripheral benzodiazepine receptors (PBRs) in the retina of the albino rabbit, Lepus cunicula, was studied by autoradiography using [H-3]-PK11195, a isoquinoline carboxamide, as a tracer. Autoradiograms obtained by directly placing the slides containing the retina sections on tritium-sensitive film provide evidence for the presence of PBRs in rabbit retina. Furthermore, the dark field examination of photomicrographs taken from autoradiograms showed two dense horizontal bands corresponding to the outer and inner photoreceptor segments, and to the inner plexiform layer. The retinal regions where [3H]-PK11195 binding was more-dense are rich in mitochondria, suggesting that as in other-neuronal tissues, retinal PBRs are involved in the mitochondrial activity. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved.