LOCALIZATION OF RECEPTORS FOR LUTEINIZING-HORMONE CHORIONIC-GONADOTROPIN IN NEURAL RETINA

Although the expression of the luteinizing hormone (LH)/human chorioni c gonadotropin (CG) receptor gene has been traditionally thought to be restricted to gonadal tissue, recent studies have shown that LH/CG re ceptors are present in many regions of the central nervous system (CNS ), as well as in peripheral tissues. We now report the characterizatio n of LH/CG receptor gene expression in the neural retina, a component of the CNS. Transcript levels in the retina are approximately equal to levels present in the cerebral cortex, but are at least 100 fold lowe r than the levels in testis. The density of LH/CG receptor transcripts , receptor protein and I-125-CG binding is the highest in the photorec eptor cells and then decreased throughout the inner retina. Our study is the first to demonstrate the presence of LH/CG receptors in the neu ral retina. This finding raises the possibility that photoreceptor cel ls have the potential to mount cellular responses to LH/CG that may im pact on visual processing, and poses an intriguing connection to the p roposed role of gonadotropins in the progression of proliferative reti nopathy.