Effects of OP-1206 alpha-CD on walking dysfunction in the rat neuropathic intermittent claudication model: comparison with nifedipine, ticlopidine and cilostazol

The systemic treatment effects of OP-1206 alpha-CD (17S-20-dimethyl-trans-delta 2-PGE1 alpha-cyclodextrin clathrate), a prostaglandin E1 (PGE1) analogue, on walking dysfunction, spinal cord blood flow (SCBF) and skin blood flow (SKBF) were assessed in the rat neuropathic intermittent claudication (IC) model in comparison with nifedipine (dimethyl 1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-3,5-pyridinedicarboxylate), ticlopidine (5-(2-chlorophenyl)methyl]-4,5,6,7-tetrahydrothieno3,2-C]pyridine hydrochloride) and cilostazol (6-4-(1-cyclohexyl-1H-tetrazol-5-yl)-butoxy]-3,4-dihydro-2(1H)-quinolinone). Two pieces of silicone rubber strips were placed in the lumbar (L4 and L6) epidural space in rats. After surgery, walking function was measured using a treadmill apparatus. SCBF and SKBF were measured using a laser-Doppler flow meter. Drugs were administered orally twice a day for 11 days from day 3 post-surgery. Treatment with OP-1206 alpha-CD significantly improved walking dysfunction on days 5, 7 and 14, and improved SCBF on day 14 post-surgery. SKBF remained unaffected. Treatment with nifedipine, ticlopidine or cilostazol had no significant effects on any of the parameters measured in this model. These data suggest that the therapeutic effect of OP-1206 alpha-CD is primarily mediated by the improved local SCBF at the territory of spinal stenosis and not due to improvement of peripheral perfusion and/or antiplatelet activity.