Characterisation and autoradiographic localisation of 5-HT3 receptor recognition sites identified with [3H]-(S)-zacopride in the forebrain of the rat.

Abstract

The pharmacological characterisation and topographical distribution of [3H]-(S)-zacopride recognition sites in the forebrain of the rat was studied using homogenate and autoradiographic radioligand binding techniques. [3H]-(S)-Zacopride labelled a single, saturable, specific binding site (defined by 10.0 microM granisetron) in homogenates prepared from the entorhinal cortex of the rat (pKD = 9.51 +/- 0.08; Bmax = 104 +/- 7 fmol mg-1 protein; mean +/- SEM, n = 8). Pharmacological characterisation of the recognition site, within the entorhinal cortex, suggested that [3H]-(S)-zacopride selectively labelled the recognition site of the 5-HT3 receptor. Specific binding of [3H]-(S)-zacopride (defin..