AIM To investigate the effects of methyl pentyl 1, 4 dihydro 2, 6 dimethyl 4 (3 nitrophenyl) 3, 5 pyridinedicarboxylate
(MN9202) on vascular smooth muscle and endothelium cells of tail artery in thrombosis rats induced by carrageenan. METHODS A thrombosis model in rats tail was established by injecting carrageenan sc. in paw. MN9202 at dosage of 1 μmol·kg -1 , ip at 24 and 1 h before and 24 h after treatment with carrageenan. Isolated vascular experiment was performed in proximal, middle and distant sections of tail artery. RESULTS Compared with those of the control group, the responses of tail arterial strips to NE (
norepinephrine), ACh (acetylcholine) and NaNO 2 decreased significantly and weaker from proximal section to distant sections. The vasorelaxation of distant strips induced by ACh and NaNO 2 was impaired completely. Compared with the model group, MN9202 partially attenuated the carrageenan induced inhibition of
vasoconstriction (mg)(135±25 vs 88±20, P <0.05)and the endothelium dependent relaxation in proximal and middle section strips, Emax being (34±3.8)% vs (27±3.1)%, and (32±3.4)% vs (24±4.5)% ( P <0 05), respectively. In addition, endothelium independent relaxation was also improved by MN9202. CONCLUSION The anti thrombosis effects of MN9202 on thrombosis rats induced by carrageenan may be in part due to the protection of vascular smooth muscle and endothelium.