Article date: 1988/6/10
PubMed ID: 2843385
Journal name: European journal of pharmacology (ISSN: 0014-2999)
The stimulatory effects of secobarbital and pregnanolone on GABA receptor binding could be distinguished by their sensitivity to blockade by phenobarbital, avermectin B1a and picrotoxinin. Phenobarbital (1 mM) and avermectin (10(-9)-10(-6) M) inhibited the stimulation of [3H]muscimol binding to pig brain membranes caused by secobarbital but not that caused by pregnanolone. In contrast, enhancement of [3H]muscimol binding by pregnanolone showed a greater sensitivity to the inhibitory effects of picrotoxinin. These results, together with data demonstrating an additivity of barbiturate- and steroid-induced effects, indicate that these two classes of modulators may interact with the GABAA receptor through different sites.
Author List: Kirkness E F, Turner A J
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Anthelmintics; Pregnanes; Receptors, GABA-A; Picrotoxin; Secobarbital; Muscimol; avermectin B(1)a; Ivermectin; picrotoxinin; Pregnanolone; Phenobarbital;
Mesh terms: Animals; Anthelmintics/pharmacology; Cerebral Cortex/drug effects; In Vitro Techniques; Ivermectin/analogs & derivatives; Muscimol/pharmacology; Phenobarbital/pharmacology; Picrotoxin/analogs & derivatives; Pregnanes/pharmacology; Pregnanolone/antagonists & inhibitors; Radioligand Assay; Receptors, GABA-A/drug effects; Secobarbital/antagonists & inhibitors; Swine; Synaptic Membranes/drug effects;