Castration differentially alters H-3 nisoxetine binding to norepinephrine uptake sites in olfactory bulb and frontal cortex of male rats
Creator
Shang Y L; Boja J W; Dluzen D E
Publisher
Synapse
Date
1999
1999-03
Description
In the present study, [H-3]nisoxetine binding to norepinephrine (NE) uptake sites and [H-3]norepinephrine uptake were investigated within olfactory bulb (OB) and frontal cortex homogenates from intact and castrated male rats. Statistically significant reductions in the number of [H-3] nisoxetine binding sites (B-max) were found in OB from the castrates, while significantly increased B-max values were obtained in the frontal cortex. Castration also significantly altered the affinity (K-d) of [H-3]nisoxetine binding in the frontal cortex, but not in the OB. Assessment of [H-3]norepinephrine uptake showed that in neither brain regions were there any statistically significant differences in K-m nor V-max between the castrated and intact male rats, indicating that the basal uptake process is not changed following castration in either of these brain areas. These results demonstrate the differential effects of castration upon [H-3]nisoxetine binding sites between the OB and frontal cortex. Such findings provide new evidence for one of the mechanisms by which androgens may modulate central noradrenergic activity. Synapse 31:250-255, 1999. (C) 1999 Wiley-Liss, Inc.