Correlation between anorectic potency and affinity for hypothalamic (+)-amphetamine binding sites of...

Area of Science:

• Neuroscience
• Pharmacology

Background:

• Phenylethylamines are known to affect appetite.
• Hypothalamic amphetamine binding sites are implicated in appetite regulation.

Purpose of the Study:

• To investigate the relationship between the anorectic effects of phenylethylamines and their binding affinities to hypothalamic sites.
• To determine if binding affinity predicts the potency of these compounds in inhibiting food intake.

Main Methods:

• Comparing the potencies of various phenylethylamines and related compounds to inhibit food intake.
• Assessing the relative affinities of these compounds for hypothalamic (+)-amphetamine binding sites in vitro.
• Analyzing the correlation between anorectic potency and binding affinity.

Main Results:

• A significant positive correlation (r = 0.78) was observed between the compounds' potencies to inhibit food intake and their affinities for hypothalamic (+)-amphetamine binding sites.
• Stereospecificity was noted for food intake inhibition by certain enantiomers, but not consistently for binding.
• Compounds without known anorectic properties, like imipramine and propranolol, showed high binding affinities.

Conclusions:

• While a correlation exists between binding affinity and appetite suppression, the functional interrelationship is uncertain.
• Hypothalamic (+)-amphetamine binding may not be the sole mechanism for the anorectic effects of all tested compounds.