Abstract
The pharmacological studies of the puffer fish poison, so called Fugu poison, has been reported by many investigators for years. Recently, the review concerned to tetrodotoxin was published by Kao (1). Since the main reason of death by puffer poison is a respiratory paralysis, the effects of tetrodotoxin on respiratory system and on skeletal muscle preparation have been noticed. Since 1952 when the crystalline tetrodotoxin was isolated from the puffer fish (2), the pharmacological actions of this purified crystalline tetrodotoxin have been studied and in 1964 the chemical structure was established (3). There have been also several studies on the smooth muscle preparations: in earlier times, it had been studied by Ishihara (4), Kimura (5), and Takahashi et al. (6, 7), and recently, on the cat's nictitating membrane by Kao (8), on guinea-pig taenia coli by Toida et al. (9, 10), and on visceral smooth muscles by Ogura (11) and Hamada (12). In the present paper, authors investigated to clarify the sites of action of crystalline tetrodotoxin on the smooth muscle preparations innervated by the sympathetic nerve.
