Benzodiazepine receptor recruitment after acute stress in synaptosomal membranes from forebrain of young chicks: action of Triton X-100.
In young chicks submitted to acute stress by forced swimming there was a significant increase in the number of the measurable [3H]-flunitrazepam receptors in synaptosomal membranes from forebrain. In addition, low subsolubilizing concentrations of Triton X-100 caused a significant increase in the measurable [3H]-flunitrazepam receptor number in synaptosomal membranes from non-stressed chicks. However, this Triton X-100 stimulatory effect was not observed when tested in synaptosomal membranes from stressed chicks. In all cases the affinity remained unchanged. This result suggest that: (i) acute stress and Triton X-100 induce receptor recruitment by enhancing [3H]-flunitrazepam accessibility to a pool of receptors which is unmeasurable either before stress or in absence of detergent; (ii) neither recruitment types are additive and they involve receptors coming from the same nonmeasurable pool; (iii) stress induces a maximal recruitment of existing benzodiazepine receptors; (iiii) the pool of nonmeasurable receptors represents about a quarter of the total in control chicks. The recruitment at a short time of stress could be interpreted in terms involving internalization; recycling or modulation of receptors but not its biosynthesis or degradation.
Martijena
I D
ID
Cátedra de Química Biológica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Argentina.
Salvatierra
N A
NA
Arce
A
A
D000208:Acute Disease; D000818:Animals; D000831:Animals, Newborn; D002645:Chickens; D003902:Detergents / Q000494:pharmacology; D005260:Female; D005445:Flunitrazepam / Q000378:metabolism; D008297:Male; D008566:Membranes / Q000378:metabolism; D017830:Octoxynol; D009994:Osmolar Concentration; D011092:Polyethylene Glycols / Q000494:pharmacology*; D016548:Prosencephalon / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism*; D012016:Reference Values; D013312:Stress, Physiological / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism*
D003902:Detergents; D011963:Receptors, GABA-A; D011092:Polyethylene Glycols; D005445:Flunitrazepam; D017830:Octoxynol