Correlation of [3H]5-hydroxytryptamine (5HT) binding to brain stem preparations and the production and prevention of myoclonus in guinea pig by 5HT agonists and antagonists.
In guinea pig brain stem preparations [3H]5-hydroxytryptamine (5HT) bound specifically to both high and low affinity sites, but specific [3H]spiperone binding was low and could not be consistently detected. This indicates a prevalence of 5HT-1 type receptors in this tissue. High affinity-specific [3H]5HT binding was more potently displaced by indole-containing 5HT agonists than by piperazine-containing 5HT agonists. This agreed with the observation that indole-containing, but not piperazine-containing compounds induced dose-dependent myoclonus in guinea pigs which originates from brain stem. The capacity of indoleamine antagonists to displace [3H]5HT-specific binding from guinea pig brain stem was similar to their reported potency in displacing [3H]5HT from 5HT-1 receptors. The [3H]5HT-labelled binding site in guinea pig brain stem is a 5HT-1 receptor and appears to be responsible for the induction of indoleamine-dependent myoclonus.
D000818:Animals; D001933:Brain Stem / Q000378:metabolism*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009207:Myoclonus / Q000139:chemically induced* / Q000517:prevention & control; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013134:Spiperone / Q000378:metabolism; D014316:Tritium
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D014316:Tritium; D012701:Serotonin; D013134:Spiperone