clen risks: good study

[West_Bank]

Found this while doing research on my endurance cycle. It is worth a look at.

a) Massive doses that humans cannot tolerate may be anabolic.
b) Permanent damage to skeletal and cardiac muscle has been demonstrated.



quote: Myotoxic effects of clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol in the rat heart and soleus muscle.


Burniston JG, Ng Y, Clark WA, Colyer J, Tan LB, Goldspink DF.

Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool L3 2ET, United Kingdom. hhsjburn@livjm.ac.jp (hhsjburn@livjm.ac.jp)

Myocyte-specific necrosis in the heart and soleus muscle of adult male Wistar rats was investigated in response to a single subcutaneous injection of the anabolic beta(2)-adrenergic receptor agonist clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol. Necrosis was immunohistochemically detected by administration of a myosin antibody 1 h before the clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol challenge and quantified by using image analysis. clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol-induced myocyte necrosis occurred against a background of zero damage in control muscles. In the heart, the clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol-induced necrosis was not uniform, being more abundant in the left subendocardium and peaking 2.4 mm from the apex. After position (2.4 mm from the apex), dose (5 mg clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol/kg), and sampling time (12 h) were optimized, maximum cardiomyocyte necrosis was found to be 1.0 +/- 0.2%. In response to the same parameters (i.e., 5 mg of clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol and sampled at 12 h), skeletal myocyte necrosis was 4.4 +/- 0.8% in the soleus. These data show significant myocyte-specific necrosis in the heart and skeletal muscle of the rat. Such irreversible damage in the heart suggests that clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol may be damaging to long-term health.

PMID: 12381771 [PubMed - indexed for MEDLINE]
quote: Characterization of adrenoceptor involvement in skeletal and cardiac myotoxicity Induced by sympathomimetic agents: toward a new bioassay for beta-blockers.


Tan LB, Burniston JG, Clark WA, Ng Y, Goldspink DF.

Academic Unit of Molecular Vascular Medicine, University of Leeds, England.

Excessive levels of catecholamines have long been known to be cardiotoxic, but less well known are their toxic effects on skeletal muscle. By using an antimyosin monoclonal antibody and quantitative methods to measure the extent of myocyte necrosis, and by employing modulators of adrenoceptors (ARs), including clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol, bupranolol, propranolol, bisoprolol, atenolol, ICI-118551, phenoxybenzamine, prazosin, and yohimbine, the involvement of ARs in isoproterenol-induced myotoxicity was characterized. In the myocardium, the toxic effects were predominantly mediated via the beta(1)-ARs. In the soleus muscle, it was almost solely via the beta(2)-ARs. Myotoxicity was also observed in the myocardium when challenged with the beta(2)-AR agonist clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol. This was found to be mediated via sympathetic presynaptic beta(2)-ARs, leading to enhanced release of norepinephrine. This effect was abolished by prior treatment with reserpine. The skeletal muscle was found to be more sensitive to the myotoxic effects than cardiac muscle at lower doses of beta-AR agonists. These experiments introduce a new way of assaying beta-AR antagonists by classifying them according to their ability to prevent catecholamine-induced myotoxicity. Further research along these lines may deepen understanding of which beta-blockers work best in heart failure therapy.

PMID: 12658052 [PubMed - indexed for MEDLINE]
quote: Dose-dependent separation of the hypertrophic and myotoxic effects of the beta(2)-adrenergic receptor agonist clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol in rat striated muscles.


Burniston JG, Clark WA, Tan LB, Goldspink DF.

Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Webster Street, Liverpool L3 2ET, UK.

Muscle growth in response to large doses (milligrams per kilogram) of beta(2)-adrenergic receptor agonists has been reported consistently. However, such doses may also induce myocyte death in the heart and skeletal muscles and hence may not be safe doses for humans. We report the hypertrophic and myotoxic effects of different doses of clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol. Rats were infused with clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol (range, 1 mug to 1 mg.kg(-1)) for 14 days. Muscle protein content, myofiber cross-sectional area, and myocyte death were then investigated. Infusions of >/=10 mug.kg(-1).d(-1) of clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol significantly (P < 0.05) increased the protein content of the heart (12%-15%), soleus (12%), plantaris (18%-29%), and tibialis anterior (11%-22%) muscles, with concomitant myofiber hypertrophy. Larger doses (100 mug or 1 mg) induced significant (P < 0.05) myocyte death in the soleus (peak 0.2 +/- 0.1% apoptosis), diaphragm (peak 0.15 +/- 0.1% apoptosis), and plantaris (peak 0.3 +/- 0.05% necrosis), and significantly increased the area fraction of collagen in the myocardium. These data show that the low dose of 10 mug.kg(-1).d(-1) can be used in rats to investigate the anabolic effects of clen (http://search.store.yahoo.com/cgi-bin/nsearch?catalog=yhst-20189112917352&query=clen&.autodone=http%3A%2F%2Fwww.cemproducts.com%2Fnsear ch.html)buterol in the absence of myocyte death. Muscle Nerve, 2006.

PMID: 16411205 [PubMed - in process]

[medivac_driver]

I did not understand a thing in that study:D . So is it sayin that Clen can screw up the heart, in all that medical lingo did it give the dosage to avoid?

[Tyrone]

I did not understand a thing in that study:D . So is it sayin that Clen can screw up the heart, in all that medical lingo did it give the dosage to avoid?
It is on steroidsprofiles I think. If not it is very similar.

[West_Bank]

yeah I checked out the profiles at steroid.com and the author suggested using clen for 6-12 weeks:eek: . I'm no expert but I thought that might be a little long?

[Alin]

One thing to keep in mind is some of the negative clenbuterol studies were done in animals in very high doses using mg amounts and not mcg.

[Tyrone]

One thing to keep in mind is some of the negative clenbuterol studies were done in animals in very high doses using mg amounts and not mcg.
That's what I'm saying! Different species and way diff. dosage.

[hooker]

Yet....has anyone, in decades of bodybuilders using clen- ever known someone to have had any heart problems from it?

[Keyser soze]

Did I read that right - they were giving a dose of 5mg/kg?

If so that would be 454mg for a 200lb person? I can understand why there would be heart problems!!!

[FrankButcher]

Animals have loads of Beta-3 receptors, which cause muscle growth and clenbuterol is agonist to beta-3 as well, this is why it was suggested that it can cause muscle growth. Humans have very small amount of these recpetors.

[Experiment 626]

Is clen dangerous? I don`t know, is drinking too much coffee dangerous? Hell, pay attention to your body and monitor your dose accordingly. I sweat and loose fat fast at 120mcg, I get chest pains at 150-160mcg. Not a difficult call.