The Effect of Β3-Adrenoceptor Agonist (Brl37344) on Carbachol and Efs–Evoked Contractions of Isolated Ovine Detrusor Muscle Strip


Background: The concept of using β3-agonists in the treatment of overactive bladder with less side effects than the currently used anticholinergics, has been introduced recently. Objectives: The aim of this paper to report the presence of β3-AR in the ovine detrusor muscle. Methods: Appropriate sets of experiments using isolated ovine detrusor strips preparation. Cumulative effects of selected β-AR agonists including BRL37344 (BRL) were obtained on carbachol in presence and absence of propranolol and the β3-antagonist SR59230A, and EFS contracted strips. Results: All agonists tested produced concentration-dependent relaxation, the rank order of their relaxing potency in the ovine detrusor muscle was isoprenaline (ISO)>BRL> dobutamine > salbutamol. Both ISO and BRL significantly suppressed 5Hz EFS contraction at a concentration had no significant effect on 40Hz EFS contraction. Conclusion: It is concluded that β3-ARs are present abundantly in the ovine detrusor and the activation of which by the β-AR agonists suppresses the non-voiding detrusor contraction