- P-ISSN 1010-0695
- E-ISSN 2288-3339
Objectives : We have examined the relaxational response to the water extract of Rheum palmatum L. and Rheum undulatum L. on rat thoracic aorta and abdominal aorta.Methods : Segments of thoracic aorta and abdominal aorta obtained from rats immediately after delivery were mounted in organ baths superfused on a polygraph.Results : We found that the thoracic aorta segments responded to the water extract of genus Rheum with a dose-dependent vasorelaxation. At 10-4M 5-HT, the maximal contraction force were 93.5% of the maximum KCl-response. The 5-HT induced contraction at 10-4M were inhibited by 86.4% and 62.1% after addition of the high concentration of R. palmatum root (RPR) and leaf (RP) and R. undulatum root (RUR) and leaf (RUL). At 10 ㎎/㎖l RPR and RUR, the relaxational response at thoracic aorta and abdominal aorta with and without endothelium were 86.4%, 83.2%, 85.8%, and 62.1% of the maximum 5-HT induced contraction.Conclusion : In conclusion, our result showed that RPL and RUL induced dose-dependent vasorelaxation on rat thoracic aorta and abdominal aorta and RPL and RUL root have more potent effect than leaf.