Related Experiment Video
Updated: Jun 6, 2026
Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice
Published on: September 17, 2015
[The positive inotropic effect after washout of acetylcholine in isolated rabbit hearts]
Hai-Jian Luo1, Feng-Jie Zhang, Jun-Qiang Si
1Division of Electrophysiology, Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Ministry of Education, Shihezi University School of Medicine, Shihezi 832002, China.
Aim:
To study the regular pattern and mechanism of positive inotropic effect after washout of ACh (rebound of myocardial contractile force) in isolated rabbit hearts.
Methods:
The changes of myocardial contractile force after perfusion and washout of ACh were observed in isolated Langendorff perfused rabbit hearts.
Results:
Maximum rebound rate induced by ACh of 10(-8)-10(-3) mol/L were 2.20% +/- 1.70%, 6.71% +/- 3.40%, 9.18% +/- 3.54%, 14.16% +/- 3.27%, 4.37% +/- 5.86% and 1.03% +/- 6.86%, respectively. Compared with the ACh of 10(-5) mol/L in control group, adrenaline enhanced rebound of myocardial contractile force, maximum rebound rate in adrenaline group was 29.25% +/- 5.83% (P < 0.05), propranolol reduced rebound, and maximum rebound rate in propranolol group was 5.15% +/- 4.45% (P < 0.05), we had not detected rebound of myocardial contractile force in 800 s after addition ACh in verapamil group.
Conclusion:
In isolated rabbit heart, positive inotropic effect after washout of ACh has relevance to the activities of calcium current channel and beta-adrenergic receptor. Perhaps there are some different aspects in the mechanism of positive inotropic effect between perfusion of high concentration and after washout of ACh.
