Beta-receptors

Betanin [7659-95-2 Beta receptors Beta-santalol [77-42-9] Betavel Betaxan thins... 

Beta receptors of the beta-1 subtype mediate an increase in heart rate and increased force of contraction they are also found in the central nervous system. E and NE are equaHy potent agonists and selective antagonists are atenolol [29122-68-7] and betaxolol [63659-18-7]. Beta-2 receptors are weH known for their involvement in relaxing bronchioles. E is a more potent agonist than NE procaterol [72332-33-3] is a selective agonist ICl 118551 and a-methylpropranolol are selective antagonists. A particular amine may act on both alpha and beta receptors or predominandy on one type. NE acts mainly on alpha-1, E on both alpha and beta, and isoprotemol [7683-59-2] almost exclusively on beta receptors. Numerous antagonists also differentiate between... 

Compounds which act as antagonists at the receptors for beta sympathetic transmitters (beta blockers) have gained very wide acceptance as antihypertensive agents. It was found subsequent to their introduction that there are two populations of beta receptors the beta-1 receptors are richest in the cardiovascular system whereas beta-2 receptors are mostly found in the bronchi. Lack of receptor-type specificity led to bronchial spasm in some asthmatic individuals on ingestion of the earlier beta blockers. Much of the work outlined below had as its goal the preparation of agents which showed selectivity for beta-1 receptors. 

Tachykinin NK3 receptor TK NK3r Neurokinin-3 receptor, neurokinin B receptor, neurokinin-beta receptor, Neuromedin K receptor... 

Beta receptors are also unevenly distributed with P2-receptors the more common subtype on the effector tissues. Beta-two receptors tend to be inhibitory for example, P2-receptor stimulation causes relaxation of vascular smooth muscle and airway smooth muscle, resulting in vasodilation and bronchodilation, respectively. Beta-two receptors have a significantly greater affinity for epinephrine than for norepinephrine. Furthermore, terminations of sympathetic pathways are not found near these receptors, so P2-receptors are stimulated only indirectly by circulating epinephrine instead of by direct sympathetic nervous activity. 

Journet A et al. Towards a human repertoire of monocytic lysosomal proteins. Electrophoresis 2000 21 3411-3419. Soskic V et al. Functional proteomics analysis of signal transduction pathways of the platelet-derived growth factor beta receptor. Biochemistry 1999 38 1757-1764. Thiede B et al. A two dimensional electrophoresis database of a human Jurkat T-cell line. Electrophoresis 2000 21 2713-2720. 

Narayan, S., Thangasamy, T., and Balusu, R. 2005. Transforming growth factor beta receptor signaling in cancer. Frontiers in Bioscience 10, 1135-1145. 

Hypotensive agents—Congresses. 2. Adrenergic beta receptor blockaders—Congresses. 

There is some iiterature that examines fiavonoids such as apigenin as iigands for the estrogen beta receptor, and as an inhibitor of the enzyme estrogen synthetase (aromatase) (Kuiper et ai. 1998 Keiiis and Vickery 1984). These compounds do so potentiy, but the behaviorai significance of amounts observed in common preparations needs to be further investigated. 

Zhang XL, Topley N, Ito T, Phillips A Interleukin-6 regulation of transforming growth factor (TGF)-beta receptor compartmentalization and turnover enhances TGF-betal signaling. J Biol Chem 2005 280 12239-12245. 

Nothen, M. M., Erdmann, J., Shimron-Abarbanell, D., and Propping, P. (1994) Identification of genetic variation in the human serotonin ID beta receptor gene. Biochem. Biophys. Res. Commun. 205, 1194-1200. 

This is not the end of the story about beta blockers. Subsequent research demonstrated that there are two subclasses of beta receptors, termed beta-1 and beta-2. Both are activated by adrenaline. Both are blocked by propranolol. Beta-1 receptors are found mostly in heart muscle but not much in the lungs, whereas beta-2 receptors are found mostly in the lungs but not much in the heart. These facts provided the opportunity for better drugs. Here is the argument. 

Finally, you can increase norepinephrine activity by directly stimulating norepinephrine alpha-1 and beta receptors. Some medicines that are used to treat asthma and cardiogenic shock work in this manner, but no psychiatric medications do so. 

Blocking the beta receptor can lower blood pressure, slow heart rate, trigger erectile dysfunction (impotence), or worsen breathing difficulties in patients with asthma or emphysema. The best way to manage these side effects is to use the lowest effective dose. If the side effects remain intolerable at the least effective dose, then it s probably necessary to switch to an alternative medication. 

Propranolol Blocks NE beta receptors None Specific social anxiety disorder Agitation Lithium tremor Akathisia... 

Pindolol Blocks NE beta receptors IT Serotonin Depression (with SSRIs)... 

At the postsynaptic level, lithium has been shown to reduce the function of beta adrenoceptors, presumably by affecting the coupling between the receptor and the secondary messenger system. This effect only becomes apparent following chronic treatment, which may help to explain the delay of several days, or even weeks, before an optimal beneficial effect is observed. All antidepressants are known to reduce the functional activity of postsynaptic beta receptors, which may explain why lithium has both an antimanic and an antidepressant effect in patients with manic-depression. 

Mori, S., C. H. Heldin, and L. Claesson-Welsh. Ligand-induced polyubiquitination of the platelet-derived growth factor beta-receptor. J Biol Chem. 267 6429-34.1992. 

Mori, S., H. Kanaki, K. Tanaka, N. Morisaki, and Y. Saito. Ligand-activated platelet-derived growth factor beta-receptor is degraded through proteasome-dependent proteolytic pathway. Biochem Biophys Res Commun. 217 224-9.1995a. 

EPHEDRINE SULFATE Ephedrine sulfate is a sympathomimetic alkaloid that stimulates alpha and beta receptors as well as the CNS. It is effective orally and parenterally. It is less potent than epinephrine. 

Feldman RD, Limbird LE, Nadeau J, Robertson D, Wood AJ. Alterations in leukocyte beta-receptor affinity with aging. A potential explanation for altered beta-adrenergic sensitivity in the elderly. N Engl J Med 1984 310(13) 815-9. 

Certain beta blockers have been shown to have an antimigraine effect, including propranolol, timolol, metroprolol, and atenolol. The beneficial effect appears to be comparable for the different drugs and independent of selective beta receptor blockage. 

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