A possible role for endogenous prostaglandins in the electrophysiological effects of acetylstrophanthidin on isolated canine ventricular tissues

Circulation Research
M P MoffatM Karmazyn

Abstract

A possible role for endogenous prostaglandins in the toxic electrophysiological effects of the aglycone acetylstrophanthidin was studied in isolated canine Purkinje fiber papillary muscle preparations by standard microelectrode techniques. Acetylstrophanthidin (5 X 10(-8) g/ml) caused a significant increase in 6-keto-prostaglandin F1 alpha release from these preparations. A significant loss of membrane potential and the development of oscillatory afterpotentials was observed, as well. Administration of either of two nonsteroidal antiinflammatory agents, indomethacin (3 X 10(-5) g/ml) or aspirin (5 X 10(-5) g/ml), in the presence of acetylstrophanthidin, abolished the stimulation of 6-keto-prostaglandin F1 alpha release and delayed and attenuated the loss of membrane potential and the development of oscillatory afterpotentials. In addition, indomethacin and aspirin appeared to preserve the electrogenic pumping capacity of Purkinje fiber cells exposed to acetylstrophanthidin. Exposure of Purkinje tissues to acetylstrophanthidin inhibited post-pacing hyperpolarization normally exhibited by these tissues. Both indomethacin and aspirin decreased this inhibition. Addition of prostacyclin (1 ng/ml) after 30 minutes of exposure to acet...Continue Reading

References

May 1, 1977·Progress in Cardiovascular Diseases·G R Ferrier
Feb 1, 1974·The American Journal of Cardiology·D P ZipesG K Moe
Nov 1, 1981·Canadian Journal of Physiology and Pharmacology·M KarmazynN S Dhalla
Nov 1, 1983·Canadian Journal of Physiology and Pharmacology·M Karmazyn, N S Dhalla
Sep 1, 1962·The American Journal of Physiology·M VASSALLEB F HOFFMAN

❮ Previous
Next ❯

Citations

Sep 23, 1987·European Journal of Pharmacology·M P MoffatG R Ferrier
Oct 1, 1992·Pharmacological Research : the Official Journal of the Italian Pharmacological Society·I KanzikH Zengil
Mar 11, 2005·Autonomic & Autacoid Pharmacology·A T Demiryürek, S Demiryürek

❮ Previous
Next ❯

Related Concepts

Related Feeds

Atrial Fibrillation

Atrial fibrillation is a common arrhythmia that is associated with substantial morbidity and mortality, particularly due to stroke and thromboembolism. Here is the latest research.

Arrhythmia

Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.

Cardiac Conduction System

The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Discover the latest research on the cardiac conduction system here.