Contractile and relaxant effects of jellyfish toxin on the vascular and intestinal tissues.

1.1. 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.2.2. 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.3.3. 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.