TOADS .\.\J> SALAMAXDERS 161 



POISONS OF DERMAL GLANDS OF TOADS AND SALAMANDERS 



It has been known for centuries that toads produce poisonous sub- 

 stances. Pare in 1575 havin<r discoursed interestingly, if inaccurately, 

 on this topic. Numerous studies have been made of these poisons, 

 which are secreted by the dermal glands and therefore cannot be used 

 for poisoning either prey or enemies (except those that feed upon 

 them) ; the most extensive study being that of Faust.*''' He isolated 

 two constituents, ai)i)arently the same, in different species of toads; 

 one, which he called hufotalin, is very active, resembling the digitalis 

 group; the other, bufonin, is much less active. Bufonin is neutral in 

 reaction, soluble in warm alcohol, but slightly in cold. Analysis in- 

 dicates an empirical formula of C34H-4O0. It probably is the cause 

 of the milky appearance of the dermal secretion. P)ufotalin seems to 

 be C34ll4eOio, is acid in reaction, soluble in chlorofonn and alcohol, 

 but not in petroleum ether. Subcutaneous injection of 2.6 mg. bufo- 

 talin killed a dog (weighing 4 kg.) in four to five hours; given by 

 mouth it causes much vomiting and diarrhea, so that large doses are 

 not fatal. It causes much local irritation when applied to mucous 

 membranes, but produces no marked changes at the site of injection. 

 The effects on the circulation resemble in all respects those of the digi- 

 talis group ; bufonin acting similarly but much weaker than buf otalin. 

 Fiihner ^° considers bufotalin to be more closely related to the 

 saponins. Bufotalin seeins to be derived from bufonin by oxidation, 

 and the latter is quite similar to cholesterol, apparently having the fol- 

 lowing formula: IlO-}I.,QC-^.j~C^^lIn,-OH. An important consider- 

 ation is that Faust has also isolated from the venom of cobra and cro- 

 talus, poisons which seem related to these toad poisons, the cobra poi- 

 son being assigned an empirical formula of C-^^^H^g^^^q, and the cro- 

 talus poison C.^^H-^Ooi. 



Phisalix and Bertrand "^ have found poison in the blood of toads 

 similar to that of the glands. The hemolytic property observed by 

 Pugliese '^^ may be due to the acidity of the dermal secretion. The 

 poisons of different species seem to be quite the same in all (Faust). 

 From the dermal secretion of the large tropical toad, Bufo agua, 

 Abel and Macht ^^ have isolated two distinct active substances ; one 

 identical with epinephrine, which constitutes nearly seven per cent, of 

 the crude venom; the other, which makes up 36 per cent., is called 

 hufagin, has a composition indicated by the formula C-i^Ho^Os, and 

 therefore is presumably related to the rest of this group which arises 

 from cholesterol. In physiological action bufagin resembles digitalis, 



69 Arch. f. exp. Patli. u. Pharra., 1902 (47), 279. Complete bibliography and 

 review. 



70 Arch. exp. Path. 11. Pharni.. 1910 (6.3), 374. 



71 Arch. d. physiol. norm, ot path., 1S93 (5), 511. 



72 Arohivio di farm. e. terap., 1894 (2), 321; Arch, ital de Biol.. 1S95 (22), 79. 



73 Jour. Amer. Med. Assoc, 1911 (")(>), 1.531; Jour, of Pharm., 1912 (3), 319. 



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