Purine enzyme inhibition fails to alter benzodiazepine receptor binding in brain

Abstract

Binding of [3H]flunitrazepam to benzodiazepine receptors in brain from several species, including human, was measured in vitro in the presence and absence of purine-metabolizing enzyme inhibitors. Incubation with potent inhibitors of either adenosine deaminase (2′-deoxycoformycin and erythro-9-(2-hydroxy-3-nonyl)-adenine) or guanine deaminase (5-amino-4-imidazole carboxamide) failed to alter [3H]flunitrazepam binding in homogenates of several different regions of human, rabbit, rat or guinea pig brain. These findings are in contrast to those of Norstrand et al. [Enzyme 29, 61-65 (1983)] who reported substantial alterations in [3H]flunitrazepam binding to human brain membranes in the presence..