In the south of the country is a fungus called Ramaria flavo brunnescens that proliferates in eucalyptus biscuits and that produces poisoning of animals through its ingestion. The substances contained in this fungus responsible for such poisoning do not yet have an antidote and avoids the toxic situation in the animals, removing them from the pastures where there are eucalyptus forests and has been used as symptomatic treatment atropine. To clarify the mechanism of action of the aqueous extract of this fungus on guinea-pig smooth muscle contraction, guinea pig isolates were used in a Magnus water bath, using force transducer a coupled to the physiograph (Harvad brand, USA). The experiments were performed on 18 isolated guinea pig ileum preparations, according to the technique described above. Substances and concentrations tested by addition to the bath, selected in pilot experiments were as follows: 10 micrograms of nicotine; 24,600 micrograms of aqueous extract of the fungus Ramaria flavo brunnescens ; and 30 micrograms of Hexamethonium. The addition of the extract of said fungus produces a concentration of smooth muscle similar to that caused by nicotine, differing from that because it is not blocked by hexamethonium. This leads one to think that the death of animals that ingest the fungus is not caused by ganglionic stimulation.
