Spinal cord blood flow after intrathecal injection of a N-methyl-D-aspartate receptor antagonist or an adenosine receptor agonist in rats.

Evaluation of spinal cord blood flow (SCBF) is important as a preclinical screening for potential neurotoxicologic side effects before introducing new therapeutic drugs for intrathecal (IT) administration. This study was undertaken to determine whether two drugs with possible antinociceptive effects, the N-methyl-D-aspartate receptor antagonist 3-(2-carboxypiperazin-4- yl)propyl-1-phosphonic acid (CPP) and the adenosine agonist R-phenylisopropyladenosine (R-PIA), would affect SCBF after IT administration in the rat. SCBF was measured 30 min after IT injection of either saline, 4 nmol of CPP or 10 nmol of R-PIA in anesthetized rats by quantitative autoradiography with [ 14 C]iodantipyrine as a tracer. No differences in SCBF were found between groups treated with saline or CPP