Abstract
ENDOH, M. Differential Effects of 8-Bromo-Cyclic GMP on the Basal Contractile Force and β-Adrenoceptor-Mediated Positive Inotropic Action in the Canine Atrium. Tohoku J. exp. Med., 1983, 140 (1), 105-106-8-Bromo-cyclic GMP caused a negative inotropic action on the canine atrial muscle, whilst it did not affect the positive inotropic action of phenylephrine mediated via β-adrenoceptors. These findings are in line with the hypothesis that the muscarinic receptor stimulation may exert functional changes in the heart via two different intracellular biochemical processes: one involving cyclic AMP and the other involving cyclic GMP. 8-Bromo-cyclic GMP mimics the latter but not the former mechanism in canine atria.
