BINDING-SITES OF ZNC(C)PR, A PENTAPEPTIDE FRAGMENT OF ARGIPRESSIN, IN RAT-BRAIN

AIM: To study the binding sites of ZNC(C)PR, a C-terminal pentapeptide fragment of argipressin, in rat brain. METHODS: Using radioligand assay and radioligand [S-35]ZNC(C)PR. RESULTS: It was found that there exist native binding sites bound ZNC(C)PR with high affinity in a saturable, reversible and specific manner. Scatchard and kinetic analyses showed that these sites were homogeneous with a K-d value of 1.69 +/- 0.16 nmol . L(-1) (in the presence of MgCl2 10 mmol . L(-1)). The binding of ZNC(C)PR to the sites was at a higher level in the brain regions (such as amygdala, cortex,) and was affected by Mg2+. CONCLUSION: These binding sites represented a new type of receptors and mediated the action of ZNC(C)PR on memory.