Activation of β_2-Adrenergic Receptor Induced by Three Catecholamine Agonists:a Docking and Molecular Dynamics Study

We studied the activation of β2-adrenergic receptor（β2AR） by norepinephrine, epinephrine and isoprote- renol using docking and molecular dynamics（MD） simulation. The simulation was done on the assumption that β2AR was surrounded with explicit water and infinite lipid bilayer membrane at body temperature. So the result should be close to that under the physiological conditions. We calculated the structure of binding sites in β2AR for the three ac- tivators. We also simulated the change of the conformation ofβ2AR in the transmembrane regions（TMs）, in the mo- lecular switches, and in the conserved DRY（Aspartic acid, Arginine and Tyrosine） motif. This study provides detailed information concerning the structure ofβ2AR during activation process.

The influence of β_2AR polymorphisms as a predictor of successful short acting β_2-agonist nebulization during asthmatic exacerbation

Aim:In this study,we would like to determine associations between β2-Adrenergic Receptor(β2AR)polymorphisms at codon 16 and 27 and the response to short acting β2-agonist during asthmatic exacerbation.Methods:This was a prospective cross-sectional study of one year duration.One hundred and thirty two asthmatic patients were recruited.Five mls of venous blood was taken for DNA extraction and then genotyped for the β2AR polymorphisms using multiplex PCR.Patient's clinical responses to β2-agonist nebulization were then compared to their genotype to determine the association.Results:We found that there was no association between β2AR polymorphisms at both codon 16 and 27 with response towards short acting β2-agonist,P=0.315 and P=0.706 respectively.Conclusion:We suggested that β2AR polymorphisms at both codon 16 and 27 had no influent on the response to short acting β2-agonist.

β_2-adrenoceptor in obstructive airway diseases:Agonism, antagonism or both?

Obstructive airway disease is a complex disease entity including several maladies characterized by bronchoconstriction and abnormal airway inflammation. Reversing bronchoconstriction leads to symptomatic relief and improvement in quality of life, both in reversible(bronchial asthma) and partially reversible(chronic obstructive airway disease) obstructive airway diseases. β2-adrenoceptor expressed in human airway is the main β-receptor subtype, and its activation in airway smooth muscle cells leads to bronchodilatation. Drugs targeting β-adrenoceptors have been around for many years, for which agonists of the receptors are used in bronchodilation while antagonists are used in cardiovascular diseases. This review article summarizes the effect and usage of β2-agonist in obstructive airway disease, addressing the benefits and potential risks of β2-agonist. The article also looks at the safety of β-blocker usage for cardiovascular disease in patients with obstructive airway disease. There is also emerging evidence that non-selective β-blockers with inverse agonism ironically can have longterm beneficial effects in obstructive airway disease that is beyond cardiovascular protection. Further trials are urgently needed in this area as it might lead to a dramatic turnaround in clinical practice for obstructive airway diseases as has already been seen in the usage of β-blockers for heart failure.

围术期α_2肾上腺素受体激动剂应用进展

The α2-adrenoceptor agonists are widely applied in perioperative period because they have antinociceptive, sedative, anxiolytic, sympatholytic effects. With the development of investigation, the α2-adrenoceptor agonists’ indications are expanded and have not been investigated as a kind of adjuvant. They will not only reduce anesthetic requirements during operation, cause sedation in ICU postoperatively, offer benefits in the prophylaxis of perioperative myocardial ischaemia but probably become some kind of anesthetic by themselves in perioperative application.