scholarly journals Can the biochemical responses to a beta 2-adrenoceptor stimulant be used to assess the selectivity of beta-adrenoceptor blockers?

1983 ◽  
Vol 16 (5) ◽  
pp. 557-560 ◽  
Author(s):  
S Rolf Smith ◽  
MJ Kendall ◽  
DJ Worthington ◽  
R Holder
Keyword(s):  
Beta Adrenoceptor ◽  
Biochemical Responses ◽  
Beta 2 ◽  
Beta Adrenoceptor Blockers

ATP-sensitive K+ channel opener pinacidil augments beta 1-adrenoceptor-induced coronary vasodilation in dogs

1996 ◽  
Vol 270 (6) ◽  
pp. H2210-H2215 ◽  
Author(s):  
Y. Katsuda ◽  
K. Egashira ◽  
H. Ueno ◽  
Y. Arai ◽  
Y. Akatsuka ◽  
...  
Keyword(s):  
Metabolic Stress ◽  
K Channel ◽  
Coronary Vasodilation ◽  
Beta Adrenoceptor ◽  
Intracoronary Infusion ◽  
Channel Opener ◽  
Adrenoceptor Agonist ◽  
Anesthetized Dogs ◽  
Beta 2 ◽  
K Channel Opener

The opening of ATP-sensitive K+ (K+ATP) channels contributes to the mechanism of metabolic coronary vasodilation. The aim of the present study was to determine whether K+ATP channel opener pinacidil augments coronary vasodilation induced by beta-adrenoceptor stimulation. In anesthetized dogs, coronary vasodilation in response to intracoronary infusion of a beta 1-adrenoceptor agonist denopamine, selective beta 2-adrenoceptor stimulation with isoproterenol after bisoprolol or nitroglycerin was studied before and during simultaneous intracoronary infusion of pinacidil at a dose of 1 microgram/min, which had no effect on basal hemodynamics. Pinacidil augmented the denopamine-induced increase in coronary blood flow (CBF) from 38 +/- 9 to 66 +/- 16% (P < 0.05) but did not affect the denopamine-induced by isoproterenol or nitroglycerin. Thus pinacidil selectively augmented beta 1-adrenoceptor-mediated coronary vasodilation. These observations suggest that the K+ATP channel opener pinacidil may increase myocardial perfusion during metabolic stress associated with beta 1-adrenoceptor stimulation.

Beta adrenoceptors mediate the catecholamine-induced stimulation of oxytocin secretion from cultured bovine granulosa cells

1991 ◽  
Vol 3 (6) ◽  
pp. 715 ◽  
Author(s):  
MR Luck ◽  
M Munker
Keyword(s):  
Granulosa Cells ◽  
Receptor Subtype ◽  
Alpha Adrenoceptors ◽  
Beta Adrenoceptor ◽  
Adrenoceptor Antagonist ◽  
Adrenoceptor Agonist ◽  
Ici 118,551 ◽  
Beta 2 ◽  
Term Response

Bovine granulosa cells were treated in culture with alpha- and beta-adrenoceptor ligands to determine the receptor subtype mediating their response to catecholamines. The secretion of oxytocin by granulosa cells in serum-free medium was measured on the fourth day of culture (during the period of acquisition of a luteal phenotype). Cultures were performed in the presence of 0.5 mM ascorbic acid, which increased hormone output and potentiated the response to catecholamines. The effects of adrenaline and noradrenaline on oxytocin secretion were concentration-dependent; maximum stimulation was over 700% with adrenalin (EC50 92 nM) and 500% with noradrenaline (EC50 87 nM). The response to noradrenaline (10(-6) M) and adrenaline (10(-6) M) could be blocked by propranolol but not by phentolamine, suggesting that beta- rather than alpha-adrenoceptors were involved. Blockade by metoprolol and practolol (beta 1-adrenoceptor antagonists) was poor and dobutamine (beta 1-agonist) was weakly stimulatory. A concentration-dependent stimulatory response (EC50 200 nM) was obtained with salbutamol (beta 2-adrenoceptor agonist) and stimulation by adrenaline or salbutamol could be blocked by a selective beta 2-adrenoceptor antagonist (ICI 118,551). It is concluded that, during luteinization, the long-term response of bovine granulosa cells to stimulation induced by catecholamines is mediated through beta- rather than alpha-adrenoceptors. Although the beta 2-subtype is probably involved, the similar potencies of adrenaline and noradrenaline are uncharacteristic of beta 2-adrenoceptors and may be peculiar to the long-term response shown by these cells.

Analysis of beta-adrenoceptors mediating renin release produced by isoproterenol in conscious dogs

1980 ◽  
Vol 238 (5) ◽  
pp. F387-F393
Author(s):  
N. Himori ◽  
A. Izumi ◽  
T. Ishimori
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oral Dose ◽  
Plasma Renin ◽  
Conscious Dogs ◽  
Renin Release ◽  
Blocking Drug ◽  
Beta Adrenoceptors ◽  
Beta Adrenoceptor ◽  
Beta 2

Types of beta-adrenoceptors mediating renin release induced by isoproterenol were investigated in conscious dogs. The nonselective beta-adrenoceptor blocking drugs propranolol, D-32, and pindolol significantly inhibited increases in heart rate and plasma renin activity and a fall of blood pressure produced by intravenous infusion of isoproterenol (10 microgram . kg-1 . 20 min-1). d-Propranolol and d-D-32 did not inhibit these three responses to isoproterenol. The selective beta 1-adrenoceptor blocking drug atenolol, at the oral dose of 6 mg/kg, which selectively suppressed isoproterenol-induced tachycardia, significantly inhibited the renin release caused by isoproterenol. By contrast, the renin release induced by isoproterenol was not modified by the selective beta 2-adrenoceptor blocking drug IPS-339 at an oral dose of 3 mg/kg, which fully and selectively antagonized the fall of blood pressure in response to isoproterenol. There was good correlation between suppression of isoproterenol-induced renin release and that of isoproterenol-induced tachycardia after various beta-adrenoceptor blocking drugs. These results lead to the conclusion that in conscious dogs the beta-adrenoceptors mediating release are mainly of the beta 1 type.

scholarly journals Prognostic value of pharmacotherapy in patients with atrial fibrillation after radiofrequency ablation

2021 ◽  
Vol 23 (6) ◽  
pp. 772-777
Author(s):  
M. S. Brynza ◽  
O. V. Bilchenko ◽  
O. S. Makharynska ◽  
M. I. Shevchuk
Keyword(s):  
Atrial Fibrillation ◽  
Radiofrequency Ablation ◽  
Cardiovascular Events ◽  
Patient Survival ◽  
Supraventricular Arrhythmia ◽  
Beta Adrenoceptor ◽  
Before And After ◽  
Beta Adrenoceptor Blockers

The aim of the work: to evaluate the prognostic effect of pharmacotherapy before and after radiofrequency ablation (RFA) in patients with atrial fibrillation (AF) on all-cause mortality, supraventricular arrhythmia recurrence and non-fatal cardiovascular events. Materials and methods. Patients with paroxysmal, persistent and long-term persistent forms of AF were examined before and after RFA – isolation of pulmonary veins. The primary endpoint was patient survival, secondary – a composite endpoint of freedom from recurrence and/or non-fatal cardiovascular events for 2 years of a follow-up. Frequency and doses of pharmacotherapy were evaluated. Standard statistical procedures were used for initial data evaluation. Results. 116 patients were consecutively enrolled in the study. In the long-term post-ablation, 23 patients (19.8 %) continued to take amiodarone, 2 patients (1.7 %) – propafenone for arrhythmic events, 38 patients (32.8 %) needed anticoagulants, and 37 patients (31.9 %) received beta-adrenoceptor blockers over the entire follow-up period. The use of RAAS inhibitors decreased from 81.0 % before the ablation to 56.0 % in the long-term period following RFA. Multifactorial logistic regression analysis showed that the prolonged (more than 3 months) anticoagulation (P = 0.032) after RFA was an independent predictor of patient survival in the two-year follow-up; doses of anticoagulants before the procedure, use and doses of beta-adrenoceptor blockers in the long-term post-ablation period were associated with the secondary endpoint. Conclusions. RFA for AF significantly reduced the frequency of medications use in the long-term postoperatively. Independent predictors of survival were the doses of anticoagulants more than 3 months after ablation, arrhythmia recurrence and non-fatal cardiovascular events – the doses of anticoagulants before the procedure, and the use and doses of beta-adrenoceptor blockers in the long-term period after RFA.

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