clenbuterol like other asthma medications (eg ventolin)acts on beta 2 receptors which dilate bronchioli, there is a carry over to other adrenergic receptors like increasing heart rate and its force of contraction as well as contracting blood vessels. i think if your looking for its stimulating effects its more effective with oral medications and not puffers/aerosol sprays.
I believe clenbuterol, as a beta 2 adrenergic agonist, is a vasodilator. My understanding is that epinephrine causes vasoconstriction but it is so because epinephrine binds unselectively to all adrenergic receptors. It was one of my explanations why it seems (seemed) to work for my CFS: 1. Inhibiting proinflammatory cytokines similarly to antidepressants 2. Cerebral vasodilatation 3. Other means of neuroprotection
Some patients in Europe who suffer from asthma have to take clenbuterol as a long time therapy. They are advised to take 20ug two times daily. It seems to me that 40ug daily is quite a big dose-I would certainly start with 5ug daily at most but it is positive to know that people are taking such doses chronically without apparent damage to the cardiovascular system.
yes beta 2 doesnt cause blood vessels to dialate,it causes airways to relax and open up. adrenergic agonist cover 3 main receptors- alpha receptors cause vasoconstrictionof blood vessels, beta1 increases heart rate and stroke volume, beta 2 cause bronchiol dialation. bodybuilders use it for its supposed purpose on beta 3 which increases metabolism of brown fat and helps in weight loss. Basically its an upper/stimulant.
"Adrenaline reacts with both α- and β-adrenoreceptors, causing vasoconstriction and vasodilation, respectively. Although α receptors are less sensitive to epinephrine, when activated, they override the vasodilation mediated by β-adrenoreceptors. The result is that high levels of circulating epinephrine cause vasoconstriction. At lower levels of circulating epinephrine, β-adrenoreceptor stimulation dominates, producing an overall vasodilation."
"...[beta 2 agonists] act on the beta2-adrenergic receptor, thereby causing smooth muscle relaxation, resulting in dilation of bronchial passages, vasodilation in muscle and liver, relaxation of uterine muscle and release of insulin..."
Clenbuterol causes vasodilation not vasoconstriction.
alpha adrenergic receptors (stimulated by clenbuterol)cause vaso constriction, theres no vasodilation of blood vessels from clenbuterol, where your getting mixed up is that it causes smooth muscle relaxation causing bronchioles to dilate but not blood vessels to dilate. So it causes blood vessels to constrict and airways to relax and dilate. If you look up side effects of some of these drugs u will see that hypertension is a side effect, if it caused vasodilation this wouldnt occur, infact it would cause low/hypotension. In cardiogenic shock where the hearts ability to pump starts to fail and blood pressure drops, drugs like adrenaline which act on adrenegic receptors cause vasoconstriction which helps increase blood pressure and also increases heart rate. This same drug is used in severe asthmatics for its bronchodilation effect.
Alot of asthma drugs are classed as beta 2 agonists, 'mainly' but there is a carry over stimulation to the other adrenergic receptors. beta 2 vasodilation only effects the lungs and other smooth muscles like the uterus, where it is used to help delay labour in obstetric emergencies, it doesnt effect blood vessels.
I cant quote things from wikepidia just my 20 years experience of using these drugs in emergency situations like asthma, severe allergic reactions, cardiac arrests etc.
To quote again , this time from Goodman & Gilman's: "The Pharmacologic Basis of Therapeutics - 11th Ed. (2006)" from the subchapter "Adverse Effects of b2-Selective Agonists":
"Tachycardia is a common adverse effect of systemically administered b receptor agonists. Stimulation of heart rate occurs primarily via b1 receptors. It is uncertain to what extent the increase in heart rate also is due to activation of cardiac b2 receptors or to reflex effects that stem from b2 receptor-mediated peripheral vasodilation."
I don't understand why you claim that clenbuterol affects alpha AR when this textbooks claims that beta agonists lack this effect.
Tachycardia would then simply explain the increase in BP.
But what is most important in my opinion is this: There are only very few and not well functioning alpha AR in cerebral blood vessels and there are practically no alpha AR in smaller cerebral blood vessels and capillaries so even if hypothetically clenbuterol caused peripheral vasoconstriction it doesn't cause cerebral vasoconstriction.
theres no beta 2 receptors in blood vessels. What im saying about clenbuterol is that its selective of beta 2 but it does effect other adrenergic receptors to a lesser degree, where as adrenaline affects all the recptors to a similar degree, alot of asthma drugs supposedly affect beta2 but do have a carry over effect to other receptors, what im saying is that clenbuterol isnt a pure beta 2 agonist. if clenbuterol only caused peripheral vasoconstriction and not cerebral vasoconstriction, its still going to increase blood pressure.
Adrenaline affects all the adrenergic receptors, firstly it causes vasoconstriction through the alpha receptors which increases blood pressure, increase heart rate and strength of contraction of the heart through beta1 receptors and causes smooth muscle relaxation of the airways and uterus through beta 2. In your original post u said that beta 2 stimulation causes vasodilation, which i take u mean blood vessels dilate, which it doesnt, but it does cause the airways to relax and dilate.
Yes your right in that beta 2 are not suppose to have any effect on blood vessels but in some people it does(through stimulating alpha receptors), which increases their blood pressure, as well as an increase in heart rate can also do through beta 1 stimulation. Its common for cfsers to have low blood pressure and drugs that can increase heart rate or blood pressure can have a positive effect. but someone who has high blood pressure and then takes clenbuterol could be prone to having a stroke
the textbooks your getting your info from, are they saying that stimualtion of beta 2 receptors cause blood vessels to dilate or just airways dilating. Its rare to get a drug that only effects one of the adrenergic receptors, generally has a stronger affinity for a certain receptor and lesser effects on the other receptors.
I think we are crossing wires here somewhere, but lets keep trying to nut this out so we both understand each other. I have just read beta 2 dilates blood vessels to skeletal muscles, so i suppose it comes down to which receptor has the strongest affect, the alpha receptors causing constriction or beta causing dilation, at a guess i would say that the alpha receptors win out as its quite common for bodybuilders using clenbuterol to suffer from hypertension. If there was just a pure beta 2, then yes i would agree that it could lower blood pressure, but i dont know of this occuring on its own.
http://en.wikipedia.org/wiki/Clenbuterol, after reading abit more about clenbuterol it states that it is a central nervous sytem stimulant and increases blood pressure and oxygen transport as well as a brochodilator. All i can say is that maybe the vasoconstriction effects are stronger then the vasodilation effects. contraindications and cautions are hypertension. i dont think increases in heart rate would increase blood pressure as much as vasoconstriction would. I did read where salbutamol, a beta 2 agonist reduces blood pressure in the eyes. theres definately alot of relaxing and constricting going on with these drugs, it depends which is the most dominant.
...so i suppose it comes down to which receptor has the strongest affect, the alpha receptors causing constriction or beta causing dilation, at a guess i would say that the alpha receptors win out as its quite common for bodybuilders using clenbuterol to suffer from hypertension. If there was just a pure beta 2, then yes i would agree that it could lower blood pressure, but i dont know of this occuring on its own.
1. Clen and methylsynephrine both have very positive effects on me.
2. Clen has almost no affinity for alpha adrenoceptors and minimal norepinephrine releasing effects. It mainly stimulates beta 2 receptors which sit outside the sympathetic ganglion and when activated cause overall vasodilation. Beta receptor stimulation in the cns may however cause increased overall sympathetic outflow.
Have you looked into CCSVI I did the testing and saw that my jugulars veins are blocked literally. I saw the testing as it was done and watched the blood flow literally halt and back up as it was trying to get through. Its scary and I think that threes a big vascular component to CFS/ME and other things too.
So true!! I had Lyme Positive test for a long time and I have been able to get a bacterial DNA test showing it has cleared after treating for years. It is chronic that is for sure I believe this absolutely like any other infection can be.
If your immune system is taxed and your fighting various things it is a matter of time before those things pile up and you are overwhelmed.
I have approached things by trying to get as much information and treat the loads and help immune system as much as possible and I have made great progress. But the immune system has not been strong thing for me all my life and I have battled the infection side of things since I was born.
The immune system is so complex and its not one thing or the other exactly but I believe in genetic issues as a root start cause and then adding from there through life.