[3H]ICS 205-930 labels 5-HT3 recognition sites in membranes of cat and rabbit vagus nerve and superior cervical ganglion

Abstract

The binding characteristics of [3H]ICS 205-930, a 5-hydroxytryptamine 5-HT3 receptor antagonist, were investigated in membranes prepared from cat and rabbit vagus nerve (VN) and superior cervical ganglion (SCG). The autoradiographic localisation of 5-HT3 recognition sites was also assessed using [3H]ICS 205-930 in slices from cat medulla oblongata, nodose ganglion and vagus nerve. [3H]ICS 205-930 bound to a homogeneous population of high affinity recognition sites in cat VN: Bmax = 201 ± 43 fmol/mg protein, pKD = 9.26 ± 0.17 and SCG: Bmax = 291 ± 40 fmol/mg, pKD = 9.35 ± 0.80 (n = 3). Competition experiments performed in membranes from cat VN and SCG with agonists and antagonists suggested t..