Related Experiment Videos
Defining the histamine H2-receptor in brain: the interaction with LSD
NIDA Research Monograph
|January 1, 1978
Summary
Understanding drug action requires considering multiple receptor interactions. This study reveals H1-antagonists can act as H2-receptor antagonists, with cyproheptadine showing high potency.
Area of Science:
- Pharmacology
- Neuroscience
- Medicinal Chemistry
Background:
- Drug action is complex, involving interactions with multiple receptors.
- Defining specific receptor interactions and their consequences is challenging.
- Pharmacological effects result from a combination of receptor events.
Purpose of the Study:
- To characterize the histamine H2-receptor linked to adenylate cyclase in the brain.
- To investigate the antagonistic and agonistic activities at this receptor.
- To explore the potential of H1-antagonists and serotonin antagonists as H2-receptor modulators.
Main Methods:
- Characterization of histamine H2-receptor activity linked to adenylate cyclase.
- Assay of KB values for antagonists and ED50 values for agonists.
- Competitive antagonism studies using H1-antagonists and serotonin antagonists.
Main Results:
- H2-antagonists and H2-agonists showed expected activities at the H2-receptor-adenylate cyclase system.
- H1-antagonists, particularly cyproheptadine, exhibited potent competitive antagonism at the H2-receptor.
- D-LSD and D-2-bromo-LSD (BrLSD) were identified as competitive antagonists of histamine at the H2-receptor.
Conclusions:
- Drug interactions are multifaceted, often involving multiple receptor affinities.
- Cyproheptadine is a potent H2-receptor antagonist.
- D-LSD and BrLSD demonstrate significant H2-receptor antagonism, with BrLSD showing central effects.