Dumbacher, Beehler, Spande, Garraffo, and Daly (1992) confirmed Pitohui, an endemic genus to New Guinea, to be the first avian group to present some sort of toxin (batrachotoxin
, in this case).
, isolated from frogs belonging to the genus Phyllobates, is a very potent neurotoxin and a steroidal alkaloid that has been found to block the Na+ channels in nerves and muscles resulting in arrhythmias or cardiac arrest leading to death.
alkaloids from passerine birds: a second toxic bird genus (Ifrita ko-waldi) from New Guinea.
The different efficacies of pyrethroids on Na+ influx are consistent with previous reports that pyrethroids display distinct efficacies to either augment [3H]BTX (batrachotoxin
)-specific binding (Brown et al.
Melyrid beetles (Choresine): a putative source for the batrachotoxin
alkaloids found in poison dart frogs and toxic passerine birds.
Congratulations to John Chapman for submitting batrachotoxin
from the poison dart frog, Phyllobates terribili, as the poison used in the October 2009 "Lily Robinson and an Assassin's Tracks." John Chapman is a professor in the department of pathology and laboratory medicine at the University of North Carolina-Chapel Hill School of Medicine.
The receptors assayed included those implicated as targets of known convulsants, such as the glutamate family of receptors, nicotinic and muscarinic acetylcholine receptors, the glycine receptor, the family of [GABA.sub.A] receptor ligand sites, the batrachotoxin
site of the sodium channel (site 2) (Catterall et al.
Simply put, the patches I left for him were embedded with a highly lethal concentration of batrachotoxin
from the poison-dart frog Phyllobates terribilis.
Daly and Myers found that they could use the presence of one alkaloid, batrachotoxin
, to show that several species had a common ancestor.
Birds in the genera Pitohui and Ifrita carry batrachotoxins
, the same compounds found in some of the poison frogs of the Americas.
* Members of Central and South American rainforest tribes hunt with darts dipped in batrachotoxins
from dart-poison frog skin.
They may be piperidinic alkaloids with a ring of five carbon and one nitrogen atoms, which are found throughout the group, or they may be steroid alkaloids, known as batrachotoxins
, that are exclusive to Phyllobates.