Effects of intravenous fentanyl on spontaneous renal sympathetic nerve activity in normal and vagotomized rabbits.

Objective: To investigate the roles of sympathetic and vagus nerves in hypotension and bradycardia induced by fentanyl.

Methods: Fourteen rabbits were divided into 2 groups: normal and vagotomized rabbits. Rabbits were anesthetized, paralyzed, and artificial ventilated.

Comparison of the effects of inhalational anaesthetic agents on sympathetic activity in rabbits.

The effects of inhalational anaesthetic agents on renal sympathetic nerve activity (RSNA) were compared in anaesthetized rabbits. Concentrations of 6% desflurane, 1.2% isoflurane, and 2.

Vagally mediated sympathoexcitation and central depression by desflurane in rabbits.

The effects of desflurane on renal sympathetic nerve activity (RSNA) were studied in intact or vagotomized anaesthetized rabbits with initial concentrations of 4.5-18%, subsequently equilibrated to end-tidal concentrations from 3%, 6%, 9% and 12% each for 20 min allowing sympathetic activity to stabilize. In intact animals, immediate transient increases in mean sympathetic activity from 27% to 63% were closely related to initial concentrations from 4.

The effects of propofol on heart rate, arterial pressure and adelta and C somatosympathetic reflexes in anaesthetized dogs.

The effects of propofol on mean arterial pressure, heart rate and Adelta and C somatosympathetic reflexes, recorded in renal nerves, evoked by repeated individual supramaximal electrical stimuli applied to radial nerves, were observed in anaesthetized, paralysed and artificially ventilated dogs. Propofol was infused at rates from 0.4 to 2.

Effects of propofol and remifentanil on phrenic nerve activity and nociceptive cardiovascular responses in rabbits.

Background: The effects of propofol, remifentanil, and their combination on phrenic nerve activity (PNA), resting heart rate (HR), mean arterial pressure (MAP), and nociceptive cardiovascular responses were studied in rabbits.

Methods: Basal anesthesia and constant blood gas tensions were maintained with alpha-chloralose and mechanical ventilation. PNA, HR, MAP, and maximum changes in HR and MAP (deltaHR, deltaMAP) evoked by electrical nerve stimulation of tibial nerves were recorded.