Autoradiographic characterisation of β-adrenoceptors in chick brain using []CGP 12177

Abstract An autoradiographic method for labelling β 1 - and β 2 -adrenoceptors using [ 3 H ]CGP 12177 as a radioligand is described as well as the procedure for an autoradiographic saturation kinetic study. The method afforded higher quality autoradiographs as well as an improvement in the tissue preservation when assayed in birds and chick embryos. The results confirmed the K d values previously reported for membrane homogenate binding. The use of different radioligands to characterise β-adrenoceptors, the higher B max values found with autoradiography than those obtained by the membrane homogenate binding method and the typical errors in quantifying autoradiography are discussed. It is concluded that the method described here considerably improves autoradiographic β-adrenergic characterisation. Themes: Neurotransmitters, modulators, transporters and receptors Topics: Catecholamine receptors