Pit Viper Venom

[shaggybill]

Do all pit vipers have hemotoxic venom, or do some have neurotoxic?

Also, could someone tell me what both types of those venom do? I know hemo. has something to do with your blood, and neuro does something with your nerves, right? What are the results of each?

Thanks

[Matt]

the term "pit viper" is a very broad term.
some pit vipers do have neurotoxic venom.

neurotoxic venom attacks the nervous system causing damage to neurons and blocking synapses and possibly leading to paralysis of muscles and organs.

hemotoxic attacks the blood, resulting in hemorragic effects, internal bleeding and possibly some cellular damage to blood vessels.

***someone plese add to these if necessary, its quite a broad view on the subject***

[BWSmith]

(bear with me, I have not finished my first cup of coffee ;) )

It is a safe bet that just about all vipers will have hemotoxins. Hemos ar pretty much what matt said, but they also affect the clotting of the blood.

The sole purpose of a neurotoxin is to shut down the diaphragm, thus killing the victim (whether is be a prey item or a human from a defensive bite).

I think the best example of neurotoxins in Crotalids is the Mojave Green Rattlesnake (Crotalus scutalatus). I would also say the Eastern Diamondback Rattlesnake (Crotalus adamanteus) and the Canebrake Rattlesnake (Crotalus horridus atricaudatus).

Of course breaking down venom into 2 groups is a simplistic look at it. Snake venom is one of the most complex natural substances on the planet. It is basically a a soup of different toxins that perform individual acts (such as targeting the heart or destroying muscle tissue) or working as a group to enhance the properties of each and the overall effectiveness of the venom. Venom is also not a stagnent science. Evolution is in progress. The snakes are getting hotter. There have been found geographic variations in the neurotoxicity of the Canebrake. Rattler established.

GOD! I love this stuff!!!! :D

[J_Riley]

Originally posted by BWSmith
(The sole purpose of a neurotoxin is to shut down the diaphragm, thus killing the victim (whether is be a prey item or a human from a defensive bite).

By suffocation by stoping breathing, in case anyone doesn't know what the diaphragm is.


I have a question. Supposing by some freak chance, a turtle is envenomated with neurotoxic venom, what will happen? Seeing as turtles don't have a diaphragm? ;) Sorry, BW, just picking and yes, I saw the coffee disclaimer :p

[shaggybill]

Ok, so lets take the Copperhead for instance. Would they be more of a hemotoxic or neurotoxic venom? Is it the same for a cotton?

Also, do both hemo and neuro result in tissue loss?

[BWSmith]

Copperheads are considered Hemotoxic, same witht he Cotton. But the Cotton produces a whole other setof issues that i wont go into. To my knowledge, neurotoxins do not cause tissue damage. However many "neurotoxic" snakes have other toxins that do cause it. Naja kaouthia is a prime example.

[BWSmith]

Sorry J, forgot about your question. What the neurotoxin actually dose is block the recievers of nerve impulses so that there is no communication. Perhaps there is a reason why it seams to specifically target the diaphragm and respiritory failure is the most common cause of death (renal failure is another). As far as turtles......... i am unaware of any venomous snake that takes turtles as prey. But it would be a site to see! You think there is lump from a rat! lol

[shaggybill]

Do you know of any websites that give some pretty good info on pit viper venom? Books arent in my budget right now. Maybe after this semester...

[Matt]

This is a chart of North American species normal yeild and lethal dose of venom.
Im not sure if thats what you are looking for, but Im sure it can be of some interest to you.
http://www.venomousreptiles.org/pages/venchart

[cobraman]

Brian, you got your doo doo together on this topic. I might add that all venomous snakes have some degree of neurotoxins in their venoms. The coral snake and some of the kraits are some of the very few snakes that are almost 100% neurotoxic (having no cyto, myo, cardio, heamo, toxins) I'm with you Brian, I love this stuff!
Blessings
Ray

[cobraman]

Oh, yeah, about the turtles, the neurotoxins do not just attack the costaphrenic muscles controling the diaphragm, so my guess is that the turtle would still die.
Ray

[shaggybill]

Something else I'm confused about is when people get tagged by a rattler or cotton, they'll sometimes lose a finger or some other part of their body. What is it that does this? Is it a characteristic of either hemo or neuro, or both?

[shaggybill]

Never mind last question...I just saw it was sort of answered above. So its the hemotoxic venom that results in tissue loss, right?

[J_Riley]

yep, the beginning of the digestion process. Generally the pieces that get lost are smaller, like fingers and toes...but bad envenomations that go a long time before treatment could probably result in the loss of the entire hand...the longer the venom circulates, the more the tissue become a bunch of goo, for a lack of a scientific explaination ;)

Ray/Brian, I was just picking on Brian about the diaphragm comment with the turtle crack...I dunno, if a really hungry cotton will try and scrap road kill frogs up, I bet one would try and eat a hatchling painted turtle...hell, Nerodia eat them...

[shaggybill]

Ok. So with a decent envenomation from lets say...a cotton, how long would it take to lose a finger or toe. I know you probably dont know specifics, but could you make a guestimation. Minutes?Hours? days?

[BWSmith]

OK, Cotton bites. I'll dive in and hope I actually answer your question.

Cottonmouths are pretty unique in their bites (at least in the wild). In the wild, theya re often scavangers eating dead fish, frogs, about anything. This means that in addition to venom, there is an array of bacteria as well. Cottons are well known for causing a great deal of swelling, tissue loss, and circulatory problems. Additionally, after a cotton bite, we have to watch for gangreen, tetnis, salmonilla and several other secondary infections. The time of a bite tot he time of severe necrosis or death has way too many variables to estimate. Was it an SubCu or IV enenomation, how much venom was injected, bite site, size of the snake, physical condition of the person and a thousand other things. Necrosis CAN begin within a few minutes, a few hours, or never. Whether you lose a digit is also very much up to the doctor. Some are a little "chop happy". They tried to amputate a buddy's finger after a copper bite and he refused, now he barely has a scar. So the treatment may also lead to physical dmage such as amputation and fasciotomies which are often unnessesary. Tough question without an easy answer.

BTW, Thanks Ray ;)

[shaggybill]

Well, I certainly thank you for trying. Its nice to have a place where people dont mind answering my amateur little questions.

[BWSmith]

:)

I am at work, what better do i have to do? LOL

[hip]

I will post a question to this thread for the hot keepers who have anwsered previously above. I have heard (or I think I have in the past) about 2 phases of nerotoxic venom's.one had "pre" as a beginning and was decribed to me as deystroying the actual chemicals that make the connection between the nerves and the synapses(sorry I can't spell at all) thust the electronic signal stops at the synaptic gap unable to continue.The second was "post" as a beginning and prevented the signal from crossing by either blocking or deystroying the recieptor site at the end of the gap.I am probably wrong it was a long time ago but those still stick out in my head for some strange reason(I never got the nick name Hippy for nuthin you know) so It could be brain damage from my youth you never know someone clear this up for me please.



Thanks a hole big bunch



Hip

[shaggybill]

I think I remember reading something like that too...

[BWSmith]

That sounds correct to me. One blocks that sygnals, one blocks the receptors. I have not delved too much intot he actual mechanisms involved in the different toxins, so i am not 100% sure. I would have to do some double checking.

[J_Riley]

Cobra venom blocks the receptors, that is all I can say. Some Hungarian (European in any event) doing his PhD at Yale studied Cobras to see why some/most seemed immune to their own venom. Anyway, it turns out they (cobras) have sugar molecules that bind to the venom molecules to prevent them from blocking the receptors.