Bovine retinae were examined for their ability to bind 3H-flunitrazepam. Whole retinal homogenates revealed specific, high affinity, and saturable 3H-flunitrazepam binding (Kd, 1.1 nM; Bmax, 19.5 fmoles/mg tissue). In washed membrane preparations, 10 μM GABA caused a dramatic decrease in the Kd (42 percent). The rank order of potency for the inhibition of 3H-flunitrazepam binding by different benzodiazepines was: clonazepam > clobazam ≫ Ro 5-4864. These results are supportive for the presence of benzodiazepine receptors in the bovine retina and indicate a likeness with the previously described benzodiazepine receptors of mammalian brain.
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience