Abstract
Effects of acetylcholine (ACh) and norepinephrine on atrial contractility and pacemaker activity were investigated in isolated and blood-perfused canine atrium preparations whith a support dog which were suspended in the blood-filled bath kept at 37 degrees C. The drug was given in two forms of administration, i.e., intraarterial injection into the cannulated sinus node artery or direct administration into the bath. ACh administered into the bath produced a significant decrease in the developed tension from a concentration of 10(-5) g/ml and norepinephrine produced a significant increase in the developed tension from 3 X 10(-6) g/ml. An injection via the sinus node artery resulted in 300 and 100 times greater response to ACh and norepinephrine, respectively, in the tension development. In atrial pacemaker activity, ACh given into the bath did not produce a dose-related decrease while norepinephrine produced a dose-related increase frequently accompanied by an irregularity of rhythmicity.
Citations
Jan 1, 1992·Heart and Vessels·Y KarasawaS Chiba
Jul 20, 2000·Heart and Vessels·M Tsuboi, S Chiba
Mar 1, 1980·Clinical and Experimental Pharmacology & Physiology·S ChibaM Kobayashi
Mar 1, 1981·Clinical and Experimental Pharmacology & Physiology·S ChibaY Furukawa
Jan 1, 1983·Clinical and Experimental Pharmacology & Physiology·S Chiba, H Watanabe
Jul 6, 2000·Japanese Journal of Pharmacology·F KurogouchiS Chiba
Sep 23, 2000·Japanese Journal of Pharmacology·M Tsuboi, S Chiba
Nov 1, 1977·Clinical and Experimental Pharmacology & Physiology·S Chiba
Jan 1, 1978·Clinical and Experimental Pharmacology & Physiology·S Chiba
Sep 1, 1978·Clinical and Experimental Pharmacology & Physiology·S Chiba
Nov 1, 1978·Clinical and Experimental Pharmacology & Physiology·S Chiba
Mar 1, 1976·Clinical and Experimental Pharmacology & Physiology·S Chiba
Nov 1, 1976·Clinical and Experimental Pharmacology & Physiology·S Chiba
Jun 30, 2000·Clinical and Experimental Pharmacology & Physiology·M Tsuboi, S Chiba
Dec 1, 1984·Circulation Research·Y Furukawa, M N Levy
Feb 1, 1990·Journal of Autonomic Pharmacology·K AkahaneS Chiba
Jul 1, 1989·British Journal of Pharmacology·K AkahaneS Chiba
Oct 2, 1990·European Journal of Pharmacology·Y KarasawaS Chiba
Feb 1, 1980·Japanese Journal of Pharmacology·S ChibaM Kobayashi