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Posted by BGF on April 17, 2003 at 18:04:42:
In Reply to: Re: Distinguishing effects of venom from allergic reaction posted by Trust on April 17, 2003 at 14:35:05:
:Hmm, sounds as if this has come up before. I didn't mean to imply there was a lack of venom, but just as with bee stings (which obviously inject venom, albeit one evolved for other reasons) some people have merely nominal reactions, and some people have severe reactions.
Its interesting that you should use the bee as the example since I think that with bee, wasp, ant, etc. venoms the allergy is actually an intended side effect, a deliberate action.
> I'm wondering if people can have similarly diverse reactions to colubrid venom, from individual to individual, based on characteristics of those individuals instead of the venom. I guess what I'm getting at is that because colubrid venom, in most instances, tend to be delivered in amounts well below lethal amounts, would we be more likely to see a broad range of reactions? For deadly snakes we don't because, for example, some snakes deliver a potentially lethal bite nearly every bite, so we see severe reactions among all individuals with bites of those species. Allergic reaction, I suppose is one type of reaction, but maybe there are ways to characterize differences in reaction among individuals that don't experience a medically-defined allergic reaction.
I think with the colubrid venoms, the vast majority of 'allergic bites' are actually envenomations that were misdiagnosed.
:What is your opinion of the way in which colubrid venom works, compared to crotalid and elapid venom, in general? Do they operate similarly? Are there hemotoxic components, neurotoxic components, or is it too broad to make any generalizations?
Bit hard to make generalisations since the 'colubrids' actually are several very distinct families, some of which differ as much or more from each other as they do from elapids for example. Some examples in the variation in venoms are that Colubrinae (Boiga, Trimorphodon, Telescopus, etc.) by and large are have small, neurotoxic peptides while the Xendontinae (Heterodon, Hydrodynastes, ect.) have large enzymes that act more locally. The Natricinae include species (such as Rhabdophis sp.) that are potently blood acting. However, at least one Colubrinae (Dispholidus) is also potently blood acting as are some of the Xendontinae (such as Philodryas).
However, these are but three of the several families and further to that, we've only studied a small percentage of the species. However, what we've found has been very startling (the publications are being submitted and should start rolling out in the journals in a couple months. More on them later).
All the best