Differences in adenosine A-1 and A-2 receptor density revealed by autoradiography in methylxanthine-sensitive and insensitive mice.
Two strains of inbred mice, CBA/J and SWR/J, have been identified which are, respectively, sensitive and insensitive to the behavioral and toxic effects of methylxanthines. Autoradiographic analyses of brain adenosine receptors were conducted with [3H]CHA to label adenosine A-1 receptors and [3H]NECA, in the presence of 50 nM CPA, to label adenosine A-2 receptors. For both mouse strains, adenosine A-1 receptors were most highly concentrated in the hippocampus and cerebellum whereas adenosine A-2 receptors were selectively localized in the striatum. CBA/J mice displayed a 30% greater density of adenosine A-1 receptors in the hippocampal CA-1 and CA-3 regions and in the cerebellum as compared to the SWR/J mice. The number of A-2 receptors (Bmax) was 40% greater in the striatum and olfactory tubercle of CBA/J as compared to SWR/J mice. No significant regional differences in A-1 or A-2 receptor affinities were observed between these inbred strains of mice. These results indicate that the differential sensitivity to methylxanthines between these mouse strains may reflect a genetically mediated difference in regional adenosine receptor densities.
Jarvis
M F
MF
Research Department, CIBA-GEIGY Corporation, Summit, NJ 07901.
Williams
M
M
D000241:Adenosine / Q000031:analogs & derivatives / Q000378:metabolism; D019830:Adenosine-5'-(N-ethylcarboxamide); D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D002110:Caffeine / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D008815:Mice, Inbred Strains; D009928:Organ Specificity; D011983:Receptors, Purinergic / Q000378:metabolism*; D013045:Species Specificity; D014316:Tritium
D011983:Receptors, Purinergic; D014316:Tritium; D019830:Adenosine-5'-(N-ethylcarboxamide); D002110:Caffeine; D000241:Adenosine