Research Article

The Differential Effects of a Selective Kappa-Opioid Receptor Agonist, U50488, in Guinea Pig Heart Tissues

Figure 1

Effect of U50488 on the contractile force in guinea pig atria and ventricle. Sinoatrial node of right atrium was removed. Atria and ventricle were paced at 2 Hz. After equilibrium for 30 min, U50488 and norBNI were added sequentially. (a) Left atrium. (b) Right atrium. (c) Right ventricle.
(a) Left atrium
(b) Right atrium
(c) Right ventricle