Brain soluble fractions which modulate Na+, K+-ATPase activity likewise modify muscarinic receptor.
Two brain soluble fractions, named peaks I and II, which respectively stimulate and inhibit neuronal Na+, K+-ATPase activity, have been isolated by gel filtration in Sephadex G-50. Since cholinergic transmission seems related to such enzyme activity, in this study we evaluated the effect of brain peak I, peak II, a more purified fraction II-E and commercial ouabain, on specific binding of the muscarinic antagonist [3H]quinuclidinyl benzilate to membranes from rat cerebellum, hippocampus and cerebral cortex. We found that binding was increased by peak I and decreased by peak II, II-E and ouabain, all effects proving concentration-dependent. Since the changes exerted on the muscarinic receptor followed a pattern similar to the one already described for synaptosomal membrane Na+, K+-ATPase activity, both systems seem to interact at a functional level.
Rodríguez de Lores Arnaiz
G
G
Instituto de Biología Celular y Neurociencias Prof. Eduardo De Robertis, Facultad de Medicina, PROBICENE-CONICET, Universidad de Buenos Aires, Argentina. grodrig@ffyb.uba.ar
Schneider
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P
Peña
C
C
D000818:Animals; D001923:Brain Chemistry; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013574:Synaptosomes / Q000201:enzymology; D014020:Tissue Extracts / Q000494:pharmacology*; D014316:Tritium
D011976:Receptors, Muscarinic; D014020:Tissue Extracts; D014316:Tritium; D010042:Ouabain; D011813:Quinuclidinyl Benzilate; D000254:Sodium-Potassium-Exchanging ATPase