Recruitment of peripheral-type benzodiazepine receptors after acute stress in chick forebrain membranes: action of Triton X-100.
A significant increase in the number of measurable [3H]Ro 5-4864 receptors was found in forebrain membranes of chicks submitted to 15 min of acute swim stress compared to non-stressed chicks. In addition, low subsolubilizing concentrations of Triton X-100 caused a significant increase in the measurable [3H]Ro 5-4864 receptor number in forebrain membranes from non-stressed chicks. However, this increase caused by Triton X-100 was not observed when tested in forebrain membranes from stressed chicks. In all cases the affinity remained unchanged. These results suggest that: (1) acute stress and Triton X-100 induce receptor increase by enhancing [3H]Ro 5-4864 accessibility to a pool of receptors not detected before stress or in the absence of detergent; (2) the pool of non-measured receptors represents about a third of the total in control chicks; (3) the increments are not additive and could involve receptors coming from the same non-measured pool; (4) the receptor increase during a short time of stress could be explained by recruitment of receptors but not by an increase in the receptor protein biosynthesis; (5) stress induces a maximal recruitment of measurable [-3H]Ro 5-4864 receptors.
Marín
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Cátedra de Química Biológica, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Argentina.
Arce
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Martijena
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ID
D000818:Animals; D001570:Benzodiazepinones / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002645:Chickens; D003292:Convulsants / Q000378:metabolism; D007700:Kinetics; D017830:Octoxynol / Q000494:pharmacology*; D016548:Prosencephalon / Q000378:metabolism*; D011869:Radioligand Assay; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism*; D012016:Reference Values; D013315:Stress, Psychological / Q000378:metabolism*; D013550:Swimming; D014316:Tritium
D001570:Benzodiazepinones; D003292:Convulsants; D011963:Receptors, GABA-A; D014316:Tritium; C028513:4'-chlorodiazepam; D017830:Octoxynol