Barbiturate receptor sites are coupled to benzodiazepine receptors
(1980) In Proceedings of the National Academy of Sciences of the United States of America 77(12). p.7468-7472- Abstract
Barbiturates enhance the binding of [3H]diazepam to benzodiazepine receptor sites in rat brain. This effect occurs at pharmacologically relevant concentrations of barbiturates, and the relative activity of a series of compounds correlates highly with anesthetic activity of the barbiturates and with their ability to enhance postsynaptic inhibitory responses to the neurotransmitter γ-aminobutyric acid. Barbiturate enhancement of benzodiazepine binding is stereospecific, with the more active anesthetic isomers of N1-methylbarbiturates being also more active than their stereoisomers in enhancing benzodiazepine binding. The active barbiturates produce a reversible enhancement in the affinity of specific benzodiazepine... (More)
Barbiturates enhance the binding of [3H]diazepam to benzodiazepine receptor sites in rat brain. This effect occurs at pharmacologically relevant concentrations of barbiturates, and the relative activity of a series of compounds correlates highly with anesthetic activity of the barbiturates and with their ability to enhance postsynaptic inhibitory responses to the neurotransmitter γ-aminobutyric acid. Barbiturate enhancement of benzodiazepine binding is stereospecific, with the more active anesthetic isomers of N1-methylbarbiturates being also more active than their stereoisomers in enhancing benzodiazepine binding. The active barbiturates produce a reversible enhancement in the affinity of specific benzodiazepine binding with no effect on the number of binding sites. The barbiturate enhancement, but not the baseline benzodiazepine binding, is competitively inhibited by the convulsant picrotoxinin (at 1-10 μM), a drug that has been shown to label barbiturate-sensitive brain membrane sites related to the γ-aminobutyric acid receptor-ionophore complex. The barbiturate effect is also dependent upon the presence of certain anions, and only those anions, that penetrate the chloride channels regulated by γ-aminobutyric acid receptors. These results suggest that picrotoxin-sensitive barbiturate binding sites are coupled to benzodiazepine receptors in the γ-aminobutyric acid receptor-ionophore complex, and that these binding sites have the properties of pharmacologically relevant receptors that mediate at least part of the action of various nervous system depressant and excitatory drugs.
(Less)
- author
- Leeb-Lundberg, F. LU ; Snowman, A. and Olsen, R. W.
- publishing date
- 1980-12-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Proceedings of the National Academy of Sciences of the United States of America
- volume
- 77
- issue
- 12
- pages
- 7468 - 7472
- publisher
- National Academy of Sciences
- external identifiers
-
- scopus:0019301241
- pmid:6261261
- ISSN
- 0027-8424
- DOI
- 10.1073/pnas.77.12.7468
- language
- English
- LU publication?
- no
- id
- adf6cd6d-a0a3-45bc-bb1b-788d977c7de6
- date added to LUP
- 2019-06-12 12:01:47
- date last changed
- 2024-08-07 21:34:45
@article{adf6cd6d-a0a3-45bc-bb1b-788d977c7de6,
abstract = {{<p>Barbiturates enhance the binding of [<sup>3</sup>H]diazepam to benzodiazepine receptor sites in rat brain. This effect occurs at pharmacologically relevant concentrations of barbiturates, and the relative activity of a series of compounds correlates highly with anesthetic activity of the barbiturates and with their ability to enhance postsynaptic inhibitory responses to the neurotransmitter γ-aminobutyric acid. Barbiturate enhancement of benzodiazepine binding is stereospecific, with the more active anesthetic isomers of N<sup>1</sup>-methylbarbiturates being also more active than their stereoisomers in enhancing benzodiazepine binding. The active barbiturates produce a reversible enhancement in the affinity of specific benzodiazepine binding with no effect on the number of binding sites. The barbiturate enhancement, but not the baseline benzodiazepine binding, is competitively inhibited by the convulsant picrotoxinin (at 1-10 μM), a drug that has been shown to label barbiturate-sensitive brain membrane sites related to the γ-aminobutyric acid receptor-ionophore complex. The barbiturate effect is also dependent upon the presence of certain anions, and only those anions, that penetrate the chloride channels regulated by γ-aminobutyric acid receptors. These results suggest that picrotoxin-sensitive barbiturate binding sites are coupled to benzodiazepine receptors in the γ-aminobutyric acid receptor-ionophore complex, and that these binding sites have the properties of pharmacologically relevant receptors that mediate at least part of the action of various nervous system depressant and excitatory drugs.</p>}},
author = {{Leeb-Lundberg, F. and Snowman, A. and Olsen, R. W.}},
issn = {{0027-8424}},
language = {{eng}},
month = {{12}},
number = {{12}},
pages = {{7468--7472}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences of the United States of America}},
title = {{Barbiturate receptor sites are coupled to benzodiazepine receptors}},
url = {{http://dx.doi.org/10.1073/pnas.77.12.7468}},
doi = {{10.1073/pnas.77.12.7468}},
volume = {{77}},
year = {{1980}},
}