Brevetoxin-B of Gymnodinium breve toxin-induced contractions of smooth muscles due to the transmitter release from nerves

Abstract

Brevetoxin-B (BTX-B), a Gymnodinium breve toxin, isolated from the dinoflagellate, produced contraction of guinea pig ileum and rabbit aorta. Atropine (10(-6) M) and phentolamine (10(-6) M) abolished the BTX-B (10(-7) or 10(-6)-induced contraction of the ileum or aorta, respectively. Tetrodotoxin and saxitoxin (both 5 x 10(-7) M) also abolished the responses to BTX-B in the both tissues. Results suggest that BTX-B produces smooth muscle contractions through the tetrodotoxin- and saxitoxin-sensitive release of transmitters from autonomic nerves.