Alpha-1 adrenoceptors are decreased in human epileptic foci.
Cortical alpha-1 adrenoceptors were measured in tissues obtained from 10 patients immediately following temporal lobectomy for intractable partial epilepsy. At operation each patient exhibited spontaneous spiking restricted to either the anterior (n = 5) or posterior (n = 5) portion of the first two temporal gyri. Control samples were obtained from the nonspiking half of the same gyrus. Receptor-binding assays were performed on isolated cortical membranes using [3H]prazosin. There was a reduction (p less than 0.01) in the receptor density (beta max) of the sites in the epileptic foci without any change in affinity (mean +/- SEM): spiking--beta max, 160.5 +/- 11.3 fmol/mg protein; affinity, 0.17 +/- 0.04 nM; nonspiking--beta max, 218.8 +/- 15.6 fmol/mg protein; affinity 0.17 +/- 0.04 nM. This relative decrease in alpha-1 adrenoceptor density may be the substratum of a noradrenergic hyposensitivity that could contribute to a localized diminution in inhibitory mechanisms in epileptic foci.
D000328:Adult; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D011224:Prazosin; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D013702:Temporal Lobe / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery; D014018:Tissue Distribution; D014316:Tritium
D011942:Receptors, Adrenergic, alpha; D014316:Tritium; D011224:Prazosin