Antinociceptive effects in mice after intrathecal injection of 5'-N-ethylcarboxamide adenosine.
When injected intrathecally in mice in a volume of 5 microliter, adenosine had no effect on tail-flick or hot-plate reaction latencies at dosages up to 1 mM concentration. There were no other behavioral effects observed either. Injecting 1 mM of the adenosine receptor agonist, 5'-N-ethylcarboxamide adenosine (NECA) caused both motor paralysis of the hind-legs with a duration of approximately 4 h and simultaneous antinociception. A slight weakness of the hindlegs, but a profound antinociceptive effect, was observed after the 100 microM dose only. After 10 microM, there was no effect on motor behavior but still a prolongation of the tail-flick and hot-plate reaction latencies. Pretreatment with the adenosine receptor antagonist theophylline attenuated the antinociceptive effect of NECA. Activation of spinal adenosine receptors thus appears to selectively elicit analgesia.
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D019830:Adenosine-5'-(N-ethylcarboxamide); D000700:Analgesics; D000818:Animals; D007278:Injections, Spinal; D008297:Male; D051379:Mice; D010146:Pain / Q000517:prevention & control; D011930:Reaction Time / Q000187:drug effects; D011956:Receptors, Cell Surface / Q000187:drug effects; D011983:Receptors, Purinergic; D013116:Spinal Cord / Q000187:drug effects*
D000700:Analgesics; D011956:Receptors, Cell Surface; D011983:Receptors, Purinergic; D019830:Adenosine-5'-(N-ethylcarboxamide); D000241:Adenosine