Acute, stress-induced changes in the benzodiazepine/gamma-aminobutyric acid receptor complex are confined to the chloride ionophore.
Rapid and robust changes in the chloride ionophore component of the benzodiazepine/gamma-aminobutyric acid receptor complex ("supramolecular complex") were observed in the central nervous system of rats exposed to a brief, ambient temperature swim stress. Stress-induced modification of the chloride ionophore was manifest as an increase in the efficacy of halides (Cl-, Br- and I-) to enhance [3H]flunitrazepam binding. In contrast, neither gamma-aminobutyric acid-enhanced [3H]flunitrazepam binding nor [3H] flunitrazepam binding assayed in the absence of halide ions was altered by stress. Furthermore, the number of [35S]t-butylbicyclophosphorothionate binding sites and the apparent affinity of this radioligand were increased as a result of stress, as was the ability of Cl- and low concentrations of muscimol to increase the binding of this radioligand. These changes could represent the physiological attempt of an organism to compensate for stressful changes in the environment.
D000818:Animals; D001643:Bridged Bicyclo Compounds / Q000378:metabolism; D019086:Bridged Bicyclo Compounds, Heterocyclic; D001965:Bromides / Q000494:pharmacology; D002540:Cerebral Cortex / Q000378:metabolism; D002712:Chlorides / Q000032:analysis*; D005445:Flunitrazepam / Q000378:metabolism; D066298:In Vitro Techniques; D007454:Iodides / Q000494:pharmacology; D007476:Ionophores / Q000032:analysis*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000032:analysis*; D013312:Stress, Physiological / Q000378:metabolism*; D013462:Sulfur Radioisotopes; D013550:Swimming; D014316:Tritium; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D001965:Bromides; D002712:Chlorides; D007454:Iodides; D007476:Ionophores; D011963:Receptors, GABA-A; D013462:Sulfur Radioisotopes; D014316:Tritium; D005680:gamma-Aminobutyric Acid; D005445:Flunitrazepam; C037476:tert-butylbicyclophosphorothionate