Endogenous benzodiazepine receptor ligands in idiopathic recurring stupor.
"Endozepines" are endogenous ligands for the benzodiazepine recognition sites on gamma-aminobutyric acid A receptors in the nervous system. Idiopathic recurring stupor (IRS) is a syndrome of spontaneous stupor or coma that is not associated with known metabolic, toxic, or structural abnormalities but can be reversed by flumazenil, a pure benzodiazepine antagonist. We measured endozepine-2 and endozepine-4 by high-performance liquid chromatography and radioreceptor assay in serum and cerebrospinal fluid from three patients with IRS. During episodes of stupor there was a large (up to 300-fold compared with control patients) increase of endozepine-4 content in cerebrospinal fluid and serum, but a return to normal concentrations between attacks. Endozepine-4 may contribute to, or be the cause of, IRS. The reasons for abnormal concentrations of endozepine in blood and brain are unknown.
Department of Neurology, Johns Hopkins University, Baltimore, Maryland 21205.
J D
JD
Rothstein
A
A
Guidotti
P
P
Tinuper
P
P
Cortelli
P
P
Avoni
G
G
Plazzi
E
E
Lugaresi
P
P
Schoch
P
P
Montagna
D000328:Adult; D000368:Aged; D002851:Chromatography, High Pressure Liquid; D003128:Coma / Q000097:blood / Q000134:cerebrospinal fluid / Q000188:drug therapy; D026261:Diazepam Binding Inhibitor; D004569:Electroencephalography; D005069:Evaluation Studies as Topic; D005442:Flumazenil / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000097:blood / Q000134:cerebrospinal fluid / Q000502:physiology; D006180:Proton-Translocating ATPases; D011869:Radioligand Assay; D011963:Receptors, GABA-A / Q000187:drug effects; D012008:Recurrence
D026261:Diazepam Binding Inhibitor; D009419:Nerve Tissue Proteins; D011963:Receptors, GABA-A; D005442:Flumazenil; D006180:Proton-Translocating ATPases