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N-acetyl-beta-endorphin1-31 antagonizes the suppressive effect of beta-endorphin1-31 on murine splenocyte proliferation via a naloxone-resistant receptor.
- Source :
-
Biochemical and biophysical research communications [Biochem Biophys Res Commun] 1991 Mar 29; Vol. 175 (3), pp. 936-42. - Publication Year :
- 1991
-
Abstract
- High affinity binding sites for beta-endorphin1-31 (beta-EP) have been observed on transformed mononuclear cells such as the human U937 monocyte-like cell line and the murine EL4-thymoma line, and on normal murine splenocytes. Binding of beta-EP at these sites is resistant to competition by naloxone and other opiate receptor ligands but sensitive to N-acetyl-beta-endorphin1-31 (N-Ac), cations and GTP-gamma-sulfate. Thus, the following studies were done to determine the functional significance of binding beta-EP and N-Ac. beta-EP suppressed phytohemagglutinin (PHA)-stimulated [3H]thymidine uptake in a dose-dependent, naloxone-insensitive fashion. beta-Endorphin1-27, (des)-tyrosine beta-endorphin2-31, or N-Ac failed to duplicate the suppressive effect of beta-EP. However, N-Ac, which is equipotent to beta-EP at displacing 125I-beta-EP bound to murine splenocytes or U937 cells, antagonized the suppressive effect of beta-EP. Taken together with previous binding studies, the present observations suggest that beta-EP effects receptor-mediated responses on normal immunocytes that do not depend on the activation of neuronal-like opiate receptors which are naloxone-sensitive. N-Ac, which shows minimal binding to such brain opiate receptors, is a potent functional antagonist of the naloxone-insensitive immunocyte receptor for beta-EP.
- Subjects :
- Animals
Cells, Cultured
DNA Replication drug effects
Female
Kinetics
Lymphocyte Activation drug effects
Lymphocytes drug effects
Mice
Mice, Inbred Strains
Peptide Fragments antagonists & inhibitors
Phytohemagglutinins
Receptors, Opioid drug effects
Spleen
Thymidine metabolism
beta-Endorphin antagonists & inhibitors
Lymphocytes immunology
Naloxone pharmacology
Peptide Fragments pharmacology
Receptors, Opioid physiology
beta-Endorphin analogs & derivatives
beta-Endorphin pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0006-291X
- Volume :
- 175
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Biochemical and biophysical research communications
- Publication Type :
- Academic Journal
- Accession number :
- 1850996
- Full Text :
- https://doi.org/10.1016/0006-291x(91)91655-v