SHAPE CHANGE OF BLOOD PLATELETS—A MODEL FOR CEREBRAL 5‐HYDROXYTRYPTAMINE RECEPTORS?
British Journal of Pharmacology – April 01, 1979
Source: OpenAlex
Summary
Psychedelics like LSD and psilocine, alongside serotonin and mescaline, dramatically alter blood platelet shape in rabbits, acting on specific receptors. This neuroscience discovery highlights how compounds, often from chemical synthesis and alkaloids, interact with serotonin systems. Potent antagonists, including neuroleptic drugs, block these effects. While biology reveals platelet receptors differ from some brain areas, they mirror others, offering insights for medicine. This research, vital for psychedelics and drug studies, helps understand neurotransmitter receptor influence on behavior.
Abstract
In blood platelets of rabbits isolated by a stractan gradient and incubated in a protein‐poor medium, tryptamine, 5‐hydroxytryptamine (5‐HT) and derivatives, quipazine and mescaline caused a shape change. This shape change was inhibited by low concentrations of methysergide. The most potent antagonists of the 5‐HT‐induced shape change included ergoline derivatives and neuroleptic drugs, which showed high stereoselectivity. (‐f)‐Lysergic acid diethylamide ((+)‐LSD), psilocine and some N',N′‐dimethylated tryptamines acted as mixed agonist‐antagonists. The compounds found to be agonists or mixed agonist‐antagonists on platelets have previously been shown to act also as 5‐HT agonists in the central nervous system (CNS). With regard to 5‐HT antagonists, the 5‐HT receptors of platelets reacted differently from those described earlier in brain areas with dense 5‐hydroxytryptaminergic innervation, but showed similarities to 5‐HT receptors investigated previously in spinal cord, cerebral cortex and possibly reticular formation. It is concluded that platelets may be considered with caution as models for some, but not for all, 5‐HT receptors in the CNS.