Characterization of alpha, beta-methylene ATP binding sites in mouse crude synaptic membranes.
Since ATP has been reported to be a potent excitatory transmitter in the mammalian central nervous system (CNS), we studied the neurochemical characters of the binding sites of alpha,beta-methylene ATP, an agonist of P2x receptors, in mouse crude synaptic membranes. ATP and its related compounds inhibited [3H] alpha,beta-methylene ATP binding in a concentration-dependent manner. The potency order in the inhibition of the binding was as follows; alpha,beta-methylene ATP = ADP beta S > ATP gamma S > ATP > or = ADP > beta,gamma-methylene ATP >> UTP > 2-methylthio ATP. And adenosine did not affect the binding. The order was different from those reported in peripheral tissues. And Sr2+, Ca2+, Mg2+, and Cd2+ enhanced the binding. These results suggest that alpha,beta-methylene ATP binding sites in CNS have different characters from those in peripheral tissues.
Hori
S
S
Department of Pharmacology (I), Jikei University School of Medicine, Tokyo, Japan.
Kawamura
M
M
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D002412:Cations / Q000494:pharmacology; D016015:Logistic Models; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D013498:Suramin / Q000494:pharmacology; D013570:Synaptic Membranes / Q000378:metabolism*; D014227:Triazines / Q000494:pharmacology
D002412:Cations; D014227:Triazines; C012842:Cibacron Blue F 3GA; D013498:Suramin; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate