Toad toxins

Among insectivores, at least five genera of hedgehogs anoint themselves with toad toxins. Although the exact adaptive function of this behavior is not known, it has been observed that the anointed spines hurt humans more than clean ones (Brodie, 1977). 

Omoto, T., Thin-layer chromatography of toad toxin, Kagaku No Ryoiki Zokan, 64, 115, 1964. 

Khab, X1974. Narcotic use of toad toxins in southern Veracruz Unpublished ms. 

Use In modem medicine toad toxins have been replaced by the more easily accessible Digitalis glycosides. 

Other animals also make use of toad toxins, for example, after consumption of toads, hedgehogs spread saliva over their spines Like the toads, some frogs also secrete active substances from their skin glands. These highly poisonous toxins (see frog toxins) are mostly alkaloids, some of which have also been identified in toads. 

Bufotoxin the rrtain toxin in the venom of the European toad, Bufo vulgaris. The minimal lethal dose in cats is 390 pg/kg. See Toad toxins. 

Cardiotoxins in the widest sense, substances which, in toxic doses, cause heart damage and may lead to heart stoppage. They may interfere with the generation or conduction of stimuli or with the heart s own blood supply, or they may directly attack the heart muscle. In the narrower sense, they include the cardiac glycosides and their aglycones from plants, and a group of toad toxins. 

Toad toxins poisons found in the secretions of the skin glands of toads (Bufonidae) (Fig.). These are... 

The following metabolites of Tip are listed separately Actinomydns, Indican, Indigo, Indole alkaloids, Kynurenine, Melatonin, Ommochromes, Phallo-toxins, Serotonin, Toad toxins, Tryptamine, Violacein. The status of Auxin (see) as a Tip metabolite is now in question. 

Interesting information on these toads toxins can be found on the website http //www.asanltr.com/ASANews-99/995frogs.htm. 

Aquatic frogs and toads probably need less toxin for defense than terrestrial forms. The compounds in the frogs mucus are thought to be neuroleptic, blocking dopamine receptors. They also possibly are antibacterial and aid wound repair, and they are known to elevate the level of prolactin, the amphibian Juvenile hormone (Barthalmus and Zielinski, 1988). 

Norbufotenine (5-hydroxy-N-methyltryptamine, N-methylserotonin, 5-OH-NMT) This base is scattered in both the animal and the plant kingdoms. It has been found in quite a few toads and in barley shoots. It has been isolated from the herb Desmodium pulchellum. This is an interesting twilight compound lying halfway between a notorious toxin (bufotenine) and a vital neurotransmitter (serotonin). And it is unexplored, for shame. It has been detected in the urine... 

Bufogenins or Bufagins These are nitrogen-free steroidal lactones that are heart toxins found in toad venom. They have no chemical resemblance to bufotenine whatsoever. 

Why should toads cause such reactions in humans Many species of toads have evolved a spectacular defense mechanism that prevents them from becoming a predator s next meal. When frightened, the toads activate glands behind their eyes and secrete a mixture of toxins that will convince an attacker to look elsewhere for its next meal. Scientists have identified as many as fifteen different compounds in toad venom, each... 

The toxin acts on nerves to block transmissions to the muscle by increasing the permeability of membranes to sodium ions. It is specifically antagonized by tetro-dotoxin (Fig. 30-16). Batrachotoxin alkaloids are present also in certain birds.3303 Some echinoderms make powerful steroid toxins such as holothuiin A (Fig. 22-12), a surface active agent that causes irreversible destruction of the excitability of neuromuscular tissues. The common toad produces in its skin steroid toxins such as bufotoxin (Fig. 22-12), which are sufficiently powerful to teach a dog to leave toads alone. 

A new toxic alkaloid, marinobufagin 3-suberoyl-L-glutamine ester (36a), has been isolated from the skin of the poison toad (Bufo americanus). The partial synthesis of the toxin from the ester (36b) was also reported.80... 

Numerous species of amphibia (frogs, toads, newts, salamanders) produce poisons, such as bufotenin, in specialized skin secretory glands. Most of these animals pose no hazard to humans. However, some of the toxins are extremely poisonous. For example, Central American Indian hunters have used hunting arrows tipped with poison from the golden arrow frog. 

A guanidinium toxin that appears in several chromatographic systems to be identical with tetrodotoxin has been reported from the toad Brachy-cephalus ephippium of the family Brachycephalidae (209). The biological activity appeared similar to that of tetrodotoxin, but it was judged to be less potent. The name ephippiotoxin was coined, but the toxin may prove to be identical to tetrodotoxin. 

Whether Shakespeare knew of the toxins in some frogs and toads is doubtful. We don t normally associate frogs and toads with poison because they don t bite. However, some frogs and toads, for example the frog dendrobates, produce very potent toxins to ward off or even kill... 

Toads can also produce toxins, which are different from those produced by frogs, one of which, bufotenin, has similar effects to LSD, causing hallucinations and also lowering blood pressure. Another toxin, bufotahn, affects heart function like digitalis, which may lead to arrythmias and death. Cases of poisoning have occurred as a result of people handling these frogs and toads, as some of them can produce considerable amounts of the toxins. 

The toxins from Bufo species of toads are venom complexes that have a distinct cardioactive digitalislike action. Toxic signs include profuse salivation with pulmonary edema, cardiac arrhythmia, hypertension, and prostration. Convulsions and death due to cardiac arrest may occur as early as 15 min after exposure to the toxin. Susceptible populations include children and pet dogs or cats playing with toads. 

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