Amphibian poisons

Amphibian venoms is the collective name for only the defense and protection against micro-organisms serving toxins that of amphibians ( amphibians such as frogs and toads etc.) through skin glands secreted be.

Amphibian poisons include some of the strongest known poisons: batrachotoxin ( poison dart frogs ) and tetrodotoxin ( newts and puffer fish ).

The chemical composition does not reveal any uniform principle; amphibian poisons include: steroids , peptides , biogenic amines and alkaloids . From the cane toad are cardiac glycosides ( Bufadienolides ) known. In addition to samandarin, the skin glands of certain salamanders secrete the alkaloids samandenon, samin and samandaridin.

Frogs are unable to produce these toxins on their own. They are dependent on ingesting the corresponding insecticides with their prey and sequestering them in the body . Poison dart frogs bred in the terrarium are practically non-toxic. The toxins of frogs (often collectively called pumiliotoxins ) come from the diet with poisonous animals (e.g. scale ants or horn mites ). The amphibians are able to tolerate the toxins contained in the food and to accumulate in the skin. 232 poisonous alkaloids have been identified in the skin of strawberry frogs , including pumiliotoxins and allopumiliotoxins ( aPTX ) in particular .

The tetrodotoxin (TTX) of the rough-skinned yellow-bellied newt is particularly effective . It blocks voltage-activated sodium channels , which are also found in neurons . The lethal dose of tetrodotoxin is approximately 10 micrograms per kilogram of body weight.

literature

Gerhard Habermehl : Poisons as life partners . In: Chemistry in Our Time . tape 8 , no. 3 , 1974, p. 72-77 , doi : 10.1002 / ciuz.19740080303 .
Dietrich Mebs: Origin of a frog toxin. In: Naturwissenschaftliche Rundschau. 59 (5). 2006, pp. 263-264. ISSN 0028-1050 .

Single receipts

↑ ^a ^b Konrad Staudt et al .: Foraging behavior and territoriality of the strawberry poison frog (Oophaga pumilio) in dependence of the presence of ants. In: Amphibia-Reptilia , Volume 31, No. 2, 2010, pp. 217-227 doi : 10.1163 / 156853810791069100
↑ Ariel Rodríguez, Dennis Poth, Stefan Schulz, Miguel Vences: Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba. In: Biology Letters , Royal Society Publishing, online publication on November 3, 2010 doi : 10.1098 / rsbl.2010.0844
↑ Ralph A. Saporito et al. : Spatial and temporal patterns of alkaloid variation in the poison frog Oophaga pumilio in Costa Rica and Panama over 30 years. In: Toxicon , Vol. 50, No. 6, 2007, pp. 757-778.
^ Rainer Klinke: Physiology . Georg Thieme Verlag, 2010, ISBN 3-13-796006-1 , p. 66 ( limited preview in Google Book search).

[Staudt-1] Konrad Staudt et al .: Foraging behavior and territoriality of the strawberry poison frog (Oophaga pumilio) in dependence of the presence of ants. In: Amphibia-Reptilia , Volume 31, No. 2, 2010, pp. 217-227 doi : 10.1163 / 156853810791069100

[2] Ariel Rodríguez, Dennis Poth, Stefan Schulz, Miguel Vences: Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba. In: Biology Letters , Royal Society Publishing, online publication on November 3, 2010 doi : 10.1098 / rsbl.2010.0844

[3] Ralph A. Saporito et al. : Spatial and temporal patterns of alkaloid variation in the poison frog Oophaga pumilio in Costa Rica and Panama over 30 years. In: Toxicon , Vol. 50, No. 6, 2007, pp. 757-778.

[Rainer_Klinke-4] Rainer Klinke: Physiology . Georg Thieme Verlag, 2010, ISBN 3-13-796006-1 , p. 66 ( limited preview in Google Book search).