The influence of oxytocin on the fibrillation thresholds in rabbits.

The intravenous infusion of oxytocin in urethane anaesthetized rabbits induced marked increases of both atrial and ventricular fibrillation threshold. The heart rate and the arterial blood pressure (BP) diminished. Since there was no parallelism between the fibrillation threshold changes and those of heart rate and BP, it might be concluded that the changes of the fibrillation thresholds were very likely primary, i.

Effects of intravenous infusion of CaCl2 on the fibrillation thresholds in rabbits.

A study on the atrial and ventricular fibrillation thresholds performed in urethane anaesthetized rabbits showed that no significant change occurred until blood pressure was reduced to 40% of the initial value. Bilateral cervical vagotomy and the administration of propantheline did not affect these changes. (DL) propranolol (0.