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Clenbuterol & half-life

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BroDeal said:
A study about testing Clen levels in humans after eating beef injected with the drug (PDF):

http://proceedings.live-record.de/proceedings_2_pdf/2_185.pdf

It is just a few pages long.
What I find interesting is under results is this:

"All urine samples collected before and between 4 and 6 hours......... In none of the analyzed samples norandrosterone or clenbuterol were identified. Nevertheless six of the samples showed unregularities in the screening window for clenbuterol. After breaking the sample codes it was shown that all these samples belonged to the 4-6 hours urine of experiment 1. The consumed meat in this experiment was from the calf treated with clenbuterol until one day before slaughtering."

Why would a farmer/cattle rancher administer a drug to cattle or plant prior to slaughter, it's neither rational or economically sensible to do so.
 
Aug 31, 2010
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blackcat said:
yeah, but Ashenden himself, does not know everything neither.

I know some big riders used clen. IN RACING.

They dont use a product in racing that shows up, defeats the point if they are gonna get caught.

So, they have techniques to manage to pass tests. Whether catheter, or other methods.
Who mentioned Ashenden? The article I cited quoted Michel Audrun.

And even if they have ways to get around tests like using a catheter, that has nothing to do with masking agents. If you have information about those I'd like to hear it.
 
May 13, 2009
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betterlivingthruchemistry said:
you are correct. microdosing clen is pointless.

Right. Typical dose is IIRC about 60 microgram per day. It has its use as bronchodilator (asthma) and possibly weight loss drug (changes fat to muscle mass).
 
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BroDeal said:
A study about testing Clen levels in humans after eating beef injected with the drug (PDF):

http://proceedings.live-record.de/proceedings_2_pdf/2_185.pdf

It is just a few pages long.

I'm an engineer, not a bio-chemist, but this paper seems to confirm that eating clen treated beef meat can result in its transfer to the human body.

I know from a source in the USA that some Asian seafood is often contaminated withvarious drugs (as is river and groundwater iadjacent to drug companies in some countries).
 

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avanti said:
I'm an engineer, not a bio-chemist, but this paper seems to confirm that eating clen treated beef meat can result in its transfer to the human body.

This is correct, it also correspond with another scientific study posted in the big thread
 
Mar 4, 2010
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There really needs to be a threshold if this stuff is given to cows (it's illegal but that doesn't necessarily mean it's not being done). Athletes are responsible for what they put in their body but you can't expect them to know whether a piece of meat contains trace amounts of clenbuterol.
 
xmoonx said:
What I find interesting is under results is this:

"All urine samples collected before and between 4 and 6 hours......... In none of the analyzed samples norandrosterone or clenbuterol were identified. Nevertheless six of the samples showed unregularities in the screening window for clenbuterol. After breaking the sample codes it was shown that all these samples belonged to the 4-6 hours urine of experiment 1. The consumed meat in this experiment was from the calf treated with clenbuterol until one day before slaughtering."

Why would a farmer/cattle rancher administer a drug to cattle or plant prior to slaughter, it's neither rational or economically sensible to do so.

Yes, this was the "worst case" analysis. They wanted to maximize the possibility of detecting CB in the subjects. When meat from the animals last given CB 6 days before slaughter was eaten, no CB was detected in the subjects.

However, keep in mind the original studies were done with a relatively insensitive test, one that couldn't even detect one ng/ml of CB. The more sensitive test they used probably would have found some CB even in these subjects. If they could detect CB at levels 10-15x higher than AC's in the one day before slaughter study, probably levels at least as high as AC's could have been detected in animals slaughtered several days after last being given CB.
 
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bike_framed said:
Who mentioned Ashenden? The article I cited quoted Michel Audrun.

And even if they have ways to get around tests like using a catheter, that has nothing to do with masking agents. If you have information about those I'd like to hear it.

you used appeal to authority, w Audrun. I am dismissing this argument. You need to have dialogue w riders who use clen.

I do not know how they mask, or avoid +ive. But they do.

Just because I do not know how it works, does not mean I do not know some big riders use clen, and have tested -ive whilst using.

And dont ask me for every little bit of info and sources. You got a precis of my mail, so stop being pedantic. If you post regularly here, you would be more credulous of my input.
 
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Merckx index said:
This is very interesting. At first the volunteers tested negative for clenbuterol, but this was because the test was relatively insensitive. Upon using a more sensitive test, they found clenbuterol concentrations as high as 850 pg/ml. in urine--almost 20x what AC's value was. In fact, all four subjects who were analyzed more carefully had values of > 100 pg. 22-46 hours after the meat consumption. IMO, this strongly supports food contamination as a viable explanation. IOW, it has to be taken seriously, though there are other explanations.

They also note that "a 300 g meal would resemble an intake of 1.2 ug clenbuterol." This suggests yet another possibility. AC could have ingested clenbuterol in contaminated meat not at the Tour, but at some earlier time. Then he could have withdrawn blood and re-infused at the Tour. There could have been enough clenbuterol in the transfused blood to account for the low value in his urine.

BS it does. They slaughtered and sectioned that part of the animal that was treated with clen 24 hours earlier. This does not even have a miniscule chance of occurring.

They used this study where the meat and animal became an effective hypodermic, cos the beast was left with clen only 24 hours, in that muscle, that was eaten. This, has zero likelihood in any estimation.
 
JRTinMA said:
A lot of drugs are non linear, I have no idea if Clenbuterol is linear or non-linear. Pharmador's failed tests make it seem linear based on the numbers presented, 24 hour half life and test value reduced in half over two days. He failed two tests in a row and numbers were thrown around but at that concentration I think its a qual test, not quantitative. The German lab must have made a guess based on same raw data.

Oooh, that's my learning for today :D
 
blackcat said:
BS it does. They slaughtered and sectioned that part of the animal that was treated with clen 24 hours earlier. This does not even have a miniscule chance of occurring.

They used this study where the meat and animal became an effective hypodermic, cos the beast was left with clen only 24 hours, in that muscle, that was eaten. This, has zero likelihood in any estimation.

No, the meat from the injection site was given only in the nandrolone study. The CB was given orally, to calves. Nothing was said in the article about picking any particular meat in that study.

The one day withdrawal is a valid criticism, but keep in mind that all the subjects analyzed by the more sensitive test had CB concentrations much higher than Bert's. This suggests that Bert's levels could be obtained from animals that were slaughtered several days after CB administration was stopped.
 
Merckx index said:
….When meat from the animals last given CB 6 days before slaughter was eaten, no CB was detected in the subjects.

However, keep in mind the original studies were done with a relatively insensitive test, one that couldn't even detect one ng/ml of CB. The more sensitive test they used probably would have found some CB even in these subjects....
Thanks for clarifying that; as I could not for the likes of me tell (from the chart), if after using more sensitive tests if the "6 days before slaughter" sample was detected in the subjects.
 
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Merckx index said:
This suggests that if AC had taken clenbuterol in larger doses, than withdrew blood containing this clenbuterol and stored it for later transfusion, much of the clenbuterol would have been degraded. How much is difficult to estimate, since the blood would be stored at lower temperatures where metabolism would be slower. However, it appears that much of the degradation in blood takes place non-enzymatically, which means it is less sensitive to temperature.
http://www.fao.org/docrep/w4601e/w4601e06.htm

This argument also suggest why Contador would have accepted a transfusion of blood taken when he was taken clembuterol - he could have thought there wouldn't be anything suspicious in the blood at the time of the transfusion.
 
Paco_P said:
This argument also suggest why Contador would have accepted a transfusion of blood taken when he was taken clembuterol - he could have thought there wouldn't be anything suspicious in the blood at the time of the transfusion.

I should modify that conclusion I made earlier. Though I haven't found the blood data to establish it unequivocally, other data suggest CB may in fact be very stable in refrigerated blood. I now tend to believe that any CB in blood withdrawn from a rider will mostly be intact when the rider re-infuses that blood later.