Universidade Federal de Minas Gerais

In the past, the study of venoms was primarily motivated by medical considerations. An exception was the French physiologist Claude Bernard, who studied the physiological aspects of curare intoxication. A great scientific interest in venoms has arisen during the last two decades because of the demonstration that very small doses of purified toxins could modify organs and structures in a reliable and predictable way. Thus the toxins purified from animal, plant, and microbial venoms have been used successfully as tools in the in-vestigation of complex physiological processes. Two im-portant discoveries were made by Narahashi et al. (50), who showed that tetrodotoxin extracted from puffer fish venom blocked the sodium permeability in lobster giant axons, and by Lee and associates (see review in Ref. 45), who showed that ar-bungarotoxin extracted from the venom of the snake Bungarus multicinctus has a postsynaptic action, binding specifically and irre-versibly to the acetylcholine receptors in mammalian muscle. In 1971 I submitted an abstract to the Congress of the International Union of Physiological Sciences, held in Munich. In the abstract I called the attention of physiologists to one of these toxins, the tityustoxin, purified from the venom of the scorpion Tityus ser-rulatus. The title of the abstract published in the Pro-ceedings of the Congress was “Scorpion toxin, an im-portant tool for physiological research ” (30)