Neuropeptide Y receptor in the rat brain

Abstract

The specific binding of the chloramine‐T iodinated neuropeptide Y (¹²⁵I‐NPY) to membranes from rat cerebral cortex was investigated using equilibrium binding and kinetic methods. The equilibrium binding of ¹²⁵I‐NPY at 37°C was characterized by a K_d value of 0.38 nM. The receptor densities in the cerebral cortex, hypothalamus and cerebellum were 0.45 pmol/mg, 0.47 pmol/mg and 0.04 pmol/mg protein respectively. The binding site for ¹²⁵I‐NPY was sensitive to treatment with proteolytic enzymes and thiol reagents. The binding showed a sharp optimum at pH 7 ‐ 7.7 and was inhibited by increasing concentrations of Mg²⁺