adrenoceptors

adrenoceptors

transmembrane proteins on cells that are activated by noradrenaline released at sympathetic nerve endings or by circulating catecholamines. There are three main types: alpha-11), alpha-2 (α2) and beta (β) which mediate responses by different cellular mechanisms and are activated preferentially by different agonists. Each type has three subtypes. All subtypes respond strongly to noradrenaline, β most strongly to adrenaline, and certain synthetic dugs can distinguish between α1 and α2. Such differences account, for example, for smooth muscle relaxation in some tissues (β-mediated vasodilatation in skeletal muscle; bronchodilation in the lungs) and vasoconstriction in others (α-mediated, in gut and skin) during heightened sympathetic activity. International agreement is for 'adrenoceptor' but the use of 'adrenergic receptors' is still common in the USA.
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Some of the NE enters the extracellular fluid and occupies adrenoceptors on cardiovascular smooth muscle cells, increasing blood pressure.
Later, a subclass of a adrenoceptors was discovered that regulates the release of neurotransmitters.
The role of NA in thermoregulation in relation to REM sleep and its deprivation may be supported by the fact that it induces hypothermia by acting on [alpha]-1 adrenoceptors in the preoptic area (135) where such receptors have been identified on the thermosensitive neurons (136).
35) The adrenoceptors are found in high concentration with in the dynamic component of the prostate gland and influence the resting tone of the smooth muscle with in the prostate and bladder neck.
2004c), stimulatory effect on [beta]- adrenoceptors (Boskabady et al.
Adrenoceptors are important in uterine contractility but propranolol was unable to reduce spasmolytic effects of PGE by antagonizing the ([beta]-adrenoceptors.
30) These findings supported the premise that stimulation of beta-adrenoceptors with adrenoceptor agonists before an elective CS may promote postnatal respiratory and metabolic adaptation.
Their topics include the role of beta adrenoceptors in atypical anti-psychotic-mediated cognitive improvements, pediatric cardiology, the pharmaco-genomics of ophthalmic beta blockers, whether current doses used in clinical practice are effective in heart failure patients, and sexual dysfunction.
In conclusion, the results suggest that ASX-O may act in modulating the blood fluidity in hypertension, and that the antihypertensive effects of ASX-O may be exerted through mechanisms including normalization of the sensitivity of the adrenoceptor sympathetic pathway, particularly [alpha]-adrenoceptors, and by restoration of the vascular tone through attenuation of the Ang II- and reactive oxygen species (ROS)-induced vasoconstriction.
Studies (2007) have shown, "salmeterol is at least 50 times more selective for beta 2 adrenoceptors than albuterol" (p.
The authors found that certain genetic combinations (polymorphisms of the adrenoceptors [beta]-1, [beta]-2, and [alpha]-adrenoreceptors, which may affect cardiac responsiveness to catecholamines) resulted in a 10-15-fold increase in the likelihood of developing major cardiac dysfunction following SAH (Zaroff et al.