[³H]Arginine-vasopressin binding sites in the CNS of the golden hamster

Tritiated arginine⁸-vasopressin ([³H]AVP) was used to identify specific binding sites for this neuropeptide in the CNS of the golden hamster. [³H]AVP binding sites were concentrated in the dorsal, ventral and lateral septum, bed nucleus of the stria terminalis (BNST), central amygdala, hippocampus, dorsal thalamic nuclei, anterior cingulate gyrus and endopiriform nucleus. Septal-BNST [³H]AVP binding sites were further characterized using membrane preparations. Saturation analysis in septal-BNST membranes resulted in a B_max of 12.4 ± 0.82 fmol/mg protein and a K_d of 2.5 ± 0.36 nM. Pharmacological studies indicate that the binding site in the septum-BNST membranes shows selectivity similar to a V₁-type vasopressin receptor. Binding characteristics were similar to those obtained from crude septal membranes prepared from adult Long-Evans rat.