Binding of apomorphine to neural membranes

✍ Scribed by Wayne Hoss; James H. Reese; Constance Smiley

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: English
• Weight: 529 KB
• Volume: 3
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490030403

✦ Synopsis

Abstract

The intrinsic fluorescence of apomorphine has been used to measure its binding to neural membranes. A large number of relatively weak binding sites are concentrated in myelin and synaptic membrane fractions. Butyrophenones have the highest affinities for these sites – K~D~ = 43 μM for haloperidol – while dopamine and dopamine releasers and reuptake blockers, as well as a variety of other alkaloids, have much lower affinities. The sites are hydrophobic and undergo a phase transition to a highly fluid state near 26°C. Calcium is a non‐competitive inhibitor of apomorphine binding. Some of the actions of neuroleptic drugs may result from binding to these hydrophobic membrane sites in vivo, blocking conduction in small catecholamine axons.