Task: Intent Identification
Input (English): Intrathecal adenosine is antinociceptive under conditions of central sensitization, but not in response to acute stimuli in normals. The reasons for this selective circumstance of action remain unclear, but some evidence links adenosine's antinociceptive effects to release of norepinephrine by terminals in the spinal cord. The purpose of this study was to test whether spinal adenosine induces norepinephrine release selectively in settings of hypersensitivity.", 'Rats randomly assigned to spinal nerve ligation, sham operation, or no operation were anesthetized. A microdialysis fiber was implanted in the spinal cord dorsal horn at the L5-L6 level and perfused with artificial cerebrospinal fluid. After washout and a baseline sample period, adenosine at various concentrations was infused through the fiber for 150 min, and samples were collected every 15 min.', "In ligated, but not in sham or normal animals, adenosine perfusion increased norepinephrine in spinal cord microdialysates in a concentration-dependent manner. The effects of adenosine plateaued after 75 min and remained stable until the end of the experiment. Intravenous injection of selective adenosine A1 and A2 receptor antagonists revealed that adenosine's effect on spinal norepinephrine release was A1 receptor mediated.
Output (English): 0