THE CHARACTERIZATION AND REGULATION OF BENZODIAZEPINE BINDING SITES IN THE MAMMALIAN RETINA, CEREBRAL CORTEX AND KIDNEY
type: CreativeWork
description: The binding of [³H]flunitrazepam (FLU) to membranes prepared from mammalian brain, retina and kidney was investigated by means of conventional filtration assay techniques. In the mouse brain a study of the ontogeny of [³H]FLU binding was conducted. Specific [³H]FLU binding was present early in development and there was a rapid increase in receptor density (Bmax) during the first 2 weeks of neonatal life. This increase could be described by the function, a·eᵏˣ, where a = 1.8 pmol/brain, k = 0.23 weeks⁻¹ and x = time in weeks (r = 0.98). By 3-4 weeks of age, adult levels of [³H]FLU binding were reached (∼115 fmol/mg tissue). Notable changes in the equilibrium dissociation constant (K(d)) during development were not observed. γ-Aminobutyric acid (GABA) has previously been shown to increase the affinity of [³H]FLU binding in the adult rat brain; in the present studies this effect was shown to be present throughout the development of the mouse brain. Kinetic analyses of the GABA enhancement of [³H]FLU binding indicated that the change in K(d) was due to a decrease in the rate constant of dissociation (k₋₁). [³H]FLU binding has been shown to occur in the mammalian retina and it has all the characteristics of cerebral [³H]FLU binding. Monosodium glutamate (MSG) is toxic to retinal neurons and it was used to ascertain the putative cellular localization of retinal BZD binding sites. Nine weeks following neonatal MSG administration, histologic evidence showed the virtual absence of ganglion cells and a marked reduction in the number of inner nuclear neurons in MSG retinae. A corresponding 73 percent decrease in GABA content and a 77 percent decrease in the Bmax of [³H]FLU were found in the retinae from MSG treated rats as compared to controls. There were no significant changes in [³H]FLU binding in the cerebella, cerebral cortices and hypothalami from MSG treated rats. The binding of [³H]FLU was characterized for the rat kidney. Binding was specific, saturable and of moderate…
abstract: The binding of [³H]flunitrazepam (FLU) to membranes prepared from mammalian brain, retina and kidney was investigated by means of conventional filtration assay techniques. In the mouse brain a study of the ontogeny of [³H]FLU binding was conducted. Specific [³H]FLU binding was present early in development and there was a rapid increase in receptor density (Bmax) during the first 2 weeks of neonatal life. This increase could be described by the function, a·eᵏˣ, where a = 1.8 pmol/brain, k = 0.23 weeks⁻¹ and x = time in weeks (r = 0.98). By 3-4 weeks of age, adult levels of [³H]FLU binding were reached (∼115 fmol/mg tissue). Notable changes in the equilibrium dissociation constant (K(d)) during development were not observed. γ-Aminobutyric acid (GABA) has previously been shown to increase the affinity of [³H]FLU binding in the adult rat brain; in the present studies this effect was shown to be present throughout the development of the mouse brain. Kinetic analyses of the GABA enhancement of [³H]FLU binding indicated that the change in K(d) was due to a decrease in the rate constant of dissociation (k₋₁). [³H]FLU binding has been shown to occur in the mammalian retina and it has all the characteristics of cerebral [³H]FLU binding. Monosodium glutamate (MSG) is toxic to retinal neurons and it was used to ascertain the putative cellular localization of retinal BZD binding sites. Nine weeks following neonatal MSG administration, histologic evidence showed the virtual absence of ganglion cells and a marked reduction in the number of inner nuclear neurons in MSG retinae. A corresponding 73 percent decrease in GABA content and a 77 percent decrease in the Bmax of [³H]FLU were found in the retinae from MSG treated rats as compared to controls. There were no significant changes in [³H]FLU binding in the cerebella, cerebral cortices and hypothalami from MSG treated rats. The binding of [³H]FLU was characterized for the rat kidney. Binding was specific, saturable and of moderate…
author: Regan, John Ward
language: en_US
keywords: Benzodiazepines., Binding sites (Biochemistry), Flunitrazepam.
date published: 1981
date modified: 2026-07-24T00:55:47Z
provider: University of Arizona
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Arizona.

PropertyValue
property ID: Handle
value: http://hdl.handle.net/10150/281953