Selective effects of ethanol on opiate receptor subtypes in brain.

Large concentrations of ethanol in vitro decreased ligand binding to mu and delta opiate receptors in the frontal cortex of the C57BL mouse, but did not alter binding to kappa opiate receptors. Mu and delta receptors were equally sensitive to the inhibitory effect of ethanol. Since the effects of ethanol were significant only in large concentrations, ethanol may alter opiate binding through its membrane lipid-perturbing actions, and the selectivity of the effects of ethanol may reflect differences in the microenvironments of the opiate receptor subtypes in membranes.

Comparison of typical and atypical benzodiazepines on the central and peripheral benzodiazepine receptors.

The affinities of typical and atypical benzodiazepines (BZs) for 3H-flunitrazepam (FLU) and 3H-Ro 5-4864, "peripheral" BZ, binding sites in the central nervous system (CNS) were compared. Each dissociation constant (Kd) value of the 3H-FLU binding sites in the cerebellum, cortex, hippocampus and spinal cord showed the similar results, although the binding maximum (Bmax) for the cortex and cerebellum yielded the largest value and the smallest Bmax appeared in the spinal cord. In contrast, Bmax for 3H-Ro 5-4864 binding sites were about three-fold higher in the spinal cord than in the cerebellum.

The neonatal development of benzodiazepine receptor subtypes in the rat cerebral cortex and cerebellum.

The development of benzodiazepine receptor subtypes in the rat cerebral cortex and cerebellum was studied. The proportions of Type I (CL218872 sensitive binding sites) and Type II (CL218872 insensitive binding sites) in both regions of the neonatal brain were quite different from those of adult. In one day old rat cortex and cerebellum, about 95% of the benzodiazepine receptor were Type II receptor, while these receptors comprised about 50% and 15% of the total in the adult cortex and cerebellum, respectively.