Beta adrenoceptors

Because iCg values for competitive antagonists represent tme dissociation constants, these make possible quantitative interpretations of SARs. Significant use also has been made of iCg values in the quantitative comparison of receptors to determine whether receptors that respond to the same agonists are identical or whether responses produced by different agonists are initiated at the same receptors (44,46). Thus, beta-adrenoceptors in human and guinea pig preparations can be direcdy compared and selective and antagonists quantitated (Table 3). 

Kenakin, T. P., Ambrose, J. R., and Irving, P. E. (1991). The relative efficiency of beta-adrenoceptor coupling to myocardial inotropy and diastolic relaxation Organ-selective treatment of diastolic dysfunction. J. Pharmacol. Exp. Ther. 257 1189—1197. 

Hieble, JP, Bondinell, WE and Ruffolo, RR (1995) Alpha- and beta-adrenoceptors from the gene to the clinic. 1. Molecular biology and adrenoceptor subclassification. J. Med. Chem. 38 3415-3444. 

Murugaiah, KD and O Donnell, JM (1995) Facilitation of noradrenaline release from rat brain slices by beta-adrenoceptors. Naunyn-Schmiedebergs Arch. Pharmacol. 351 483--490. 

Barbato, E., Caliendo, G., Larotonda, M. L, Morrica, P., Silipo, C., Vittoria, A. Relationships between octanol-water partition data, chromatographic indices and their dependence on pH in a set of beta-adrenoceptor blocking agents. 

Hirshman CA, Zhu D, Panettieri RA, Fmala CW. Actin depolymerization via the beta-adrenoceptor in airway smooth muscle cells a novel PKA-independent pathway. Am J Physiol Cell Physiol 2001 281(5) C1468-1476. 

P Reinach, N Holmberg. (1989). Inhibition of calcium of beta adrenoceptor mediated cAMP responses in isolated bovine corneal epithelial cells. Curr Eye Res 8 85-90. 

Mallick, B. N., Singh, S. Pal, D. (2005). Role of alpha and beta adrenoceptors in locus coeruleus stimulation-induced reduction in rapid eye movement sleep in freely moving rats. Behav. Brain Res. 158, 9-21. 

Brismar, K Mogensen, L. Wetterberg, L. (1987). Depressed melatonin secretion in patients with nightmares due to beta-adrenoceptor blocking drugs. Acta Med. Scand. 221, 155-8. 

Taylor, D. C., Pownall, R., Burke, W., The absorption of beta adrenoceptor antagonists in rat in-situ small intestine the effect of lipophilicity, J. Pharm. Pharmacol. 1985, 37, 280-283. 

Johnson M. The beta-adrenoceptor. Am J Respir Crit Care Med 1998 158J5 Pt 3] 146 153. 

Cowen, P. J., Grahame-Smith, D. G., Green, A. R., and Heal, D. J. (1982) Beta-adrenoceptor agonists enhance 5-hydroxytryptamine-mediated behavioural responses. Br. J. Pharmacol.. 76 265-270. 

Ortmann, R., Martin, S., Radeke, E., and Delini-Stula, A. (1981) Interaction of beta-adrenoceptor agonists with the serotonergic system in rat brain. A behavioral study using the L-5-HTP syndrome. Naunyn Schmiedebergs Arch. Pharmacol, 316 225-230. 

Weinstock, M., Weiss, C., and Gitter, S. (1977) Blockade of 5-HT receptors in the central nervous system by beta-adrenoceptor antagonists. Neuropharmacology, 16 273-276. 

Nielsen HM, and Rassing MR (2000a) TR146 cells grown on filters as a model of human buccal epithelium IV. Permeability of water, mannitol, testosterone, and beta-adrenoceptor antagonists. Comparison to human, monkey and porcine buccal mucosa. Int. J. Pharm. 194 155-167. 

Cho SH, Oh SY, Bahn JW, et al. (2005) Association between bronchodUating response to short-acting beta-agonist and non-synonymous single-nucleotide polymorphisms of beta-adrenoceptor gene. Clin Exp Allergy. 35, 1162-1167. 

Increased density of beta adrenoceptors in cortical regions... 

Increased density of 5-HT2a receptors on the platelet membrane Decreased uptake of 3H-5-HT into platelet Increased beta adrenoceptor density on lymphocyte membrane Increased density of alpha-2 adrenoceptors on platelet membranes ) Blrmted growth hormone response to a clonidine challenge Blrmted prolactin response to a fenfluramine challenge... 

Eollowing chronic administration to rats, there is evidence that most antidepressants cause adaptive changes in S-HT a/ 5-HT2a alpha-1, alpha-2 and beta adrenoceptors, GABA-B receptors and possibly the NMDA-glutamate receptors. 

Add pindolol (a 5-HTid antagonist as well as a beta adrenoceptor antagonist), which is well researched but there are contradictory findings in the literature with regard to its efficacy. So far, the clinical data suggest that the response to a standard antidepressant is accelerated. 

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. 

Inderal containing propranolol (beta-adrenoceptor blocking agent) is used with caution in diabetic patients. 

Diclofenac is a non-steroidal anti-inflammatory drug. NSAIDs interact with both angiotensin-converting enzyme inhibitors, such as enalapril, and beta-adrenoceptor blockers, such as atenolol, resulting in antagonism to the hypotensive reaction, leading to a hypertensive reaction. NSAIDs interact with... 

There is an increased risk of hyperkalaemia when ciclosporin is given with Coversyl, which contains perindopril, an angiotensin-converting enzyme inhibitor. Risk of nephrotoxicity associated with ciclosporin is increased with concomitant use with quinolones. Ciproxin contains ciprofloxacin, which is a quinolone. Tenormin contains atenolol, which is a beta-adrenoceptor blocker and there are no interactions between these agents and ciclosporin. 

Common side-effects associated with beta-adrenoceptor blockers, such as atenolol, include fatigue, bradycardia, sleep disturbances, and peripheral vasoconstriction leading to coldness of extremities. Water-soluble beta-blockers, such as atenolol, are less likely to cause sleep disturbances and nightmares than lipid-soluble beta-blockers, such as propranolol. 

Atenolol (water soluble beta-adrenoceptor blocker) is available as 25 mg, 50 mg or 100 mg tablets. 

Beta-adrenoceptor blockers block the sympathetic system antagonising the effect on the lungs, resulting in bronchoconstriction. Non-steroidal anti-inflammatory drugs inhibit prostaglandin synthesis, which may lead to bronchoconstriction. 

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