The A1 adenosine receptor antagonist 1,3, dipropyl-8-cyclopentylxanthine (DPCPX) displays adenosine agonist properties in the FRTL5 thyroid cell line.
We have evaluated whether the type I adenosine receptor mediates adenosine's ability to inhibit thyrotropin-stimulated cyclic AMP generation and DNA synthesis in FRTL5 cells. The xanthine derivative 1,3-dipropyl-8-cyclopentylxanthine, a selective antagonist for the type 1 adenosine receptor, binds to FRTL5 with high affinity and specificity. 1,3-Dipropyl-8-cyclopentylxanthine does not alter basal cyclic AMP levels but does reverse adenosine's ability to inhibit thyrotropin-stimulated cyclic AMP generation. 1,3-Dipropyl-8-cyclopentylxanthine also potently inhibits thyrotropin-stimulated and dibutyryl cyclic AMP-stimulated [3H]-thymidine incorporation into DNA in FRTL5 cells. Thus, in FRTL5 cells, 1,3-dipropyl-8-cyclopentylxanthine displays both adenosine antagonist and adenosine agonist properties, the latter occurring at a site distal to cyclic AMP generation.
Frauman
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Charles A. Dana Research Institute, Boston, Mass.
Moses
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D000241:Adenosine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive; D003994:Bucladesine / Q000494:pharmacology; D002460:Cell Line; D000242:Cyclic AMP / Q000096:biosynthesis; D004247:DNA / Q000096:biosynthesis; D051381:Rats; D011983:Receptors, Purinergic / Q000187:drug effects / Q000502:physiology*; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism*; D013972:Thyrotropin / Q000494:pharmacology; D014970:Xanthines / Q000378:metabolism / Q000494:pharmacology*
D011983:Receptors, Purinergic; D014970:Xanthines; D003994:Bucladesine; D013972:Thyrotropin; D004247:DNA; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000242:Cyclic AMP; D000241:Adenosine