Recent studies on paralytic shellfish poison in Japan

INTRODUCTION P a r a l y t i c s h e l l f i s h p o i s o n (PSP) i s one of t h e most n o t o r i o u s m a r i n e t o x i n s known. PSP, once i n g e s t e d by humans, evokes p a r a l y s i s and o t h e r symptoms, w i t h f r e q u e n t d e a t h ( r e f . 1). I t i s e s t i m a t e d t h a t t h e number o f v i c t i m s of p a r a l y t i c s h e l l f i s h (PS) p o i s o n i n g wor ldwide between 1972-1983 exceeded 900, i n c l u d i n g 40 d e a t h s . Sommer e t a l . ( r e f . 2 ) e l u c i d a t e d t h e c o u r s e o f e v e n t s l e a d i n g t o PS p o i s o n i n g : Pro togonyaulax ( f o r m e r l y Gonyaulax) c a t e n e l l a produces PSP, and grows up t o a h i g h d e n s i t y under f a v o r a b l e e n v i r o n m e n t a l c o n d i t i o n s ; t h e organism t h e n i n f e s t s b i v a l v e s which i n t u r n may p o i s o n h u m a n s when i n g e s t e d . L a t e r , p. t a m a r e n s i s , P y r o d i n i u m b a h a m e n s e , &. bahamense var . compressa , Aphanizomenon f l o s a q u a e , e t c . , were added t o t h e l i s t of PSPp r o d u c e r s (TABLE 1). S c h a n t z e t a l . ( r e f . 3) i s o l a t e d t h e f i r s t PSP t o x i n f rom t h e Alaska b u t t e r c l a m Saxidomus g i g a n t e u s and i t was d e s i g n a t e d s a x i t o x i n (STX) l a t e r . Subsequent s t u d i e s showed t h a t PSP i s n o t composed o f STX a l o n e , b u t of more t h a n t e n components whose s t r u c t u r e s are c l o s e l y r e l a t e d t o e a c h o t h e r . Some components , such a s STX and gonpautoxin (GTX)-2, have s p e c i f i c t o x i c i t i e s comparable t o t h a t of t e t r o d o t o x i n (TTX). The minimum TABLE 1. PSP-producing p l a n k t o n S p e c i e s Area PSP components Pro togonyaulax c a t e n e l l a P. t a m a r e n s i s P. a c a t e n e l l a P. phoneus P. c o h o r t i c u l a Pyrodinium bahamense u. bahamense v a r . compressa Gymnodinium c a t e n a t um Cochlodinium s p . Aphanizomenon f l o s a q u a e P a c i f i c c o a s t s C a l i f o r n i a , B r i t i s h Columbia, A l a s k a , J a p a n , Venezuela , C h i l e Canada; Nor th Sea c o a s t s England , Denmark, W . Germany, Hol land , Norway; J a p a n B r i t i s h Columbia Nor th Sea G u l f of Thai B r u n e i , Papua New Guinea