| Abstract: | A toxic component (pCrTX) of jellyfish Carybdea rastonii (10(-8)-10(-6)g/ml) caused a contraction in both rat aorta and guinea-pig taenia coli which was partially inhibited by indomethacin or aspirin. pCrTX (10(-7)-10(-6)g/ml) relaxed the norepinephrine-induced contraction in rat aorta which was inhibited by removing endothelium or by adding methylene blue. These results suggest that a portion of the pCrTX-induced contraction is due to release of prostaglandin(s) and that the pCrTX-induced relaxation is due to release of an endothelium-derived relaxing factor. |
