We investigated the differences between males and females in the reversal effect of neostigmine on neuromuscular blockade. Thirty male and 30 female patients undergoing elective general anesthesia were studied. Vecuronium was given in all patients anesthetized with nitrous oxide, oxygen, and sevoflurane. After the surgical procedure, when T1 (1st response in train-of-four (TOF))/control returne...

We have previously shown that activation of P2X purinoceptors in the subpostremal nucleus tractus solitarius (NTS) produces a rapid bradycardia and hypotension. This bradycardia could occur via sympathetic withdrawal, parasympathetic activation, or a combination of both mechanisms. Thus we investigated the relative roles of parasympathetic activation and sympathetic withdrawal in mediating this...

Etiology of the negative chronotropic response to coronary artery occlusion was studied in chloralose-anesthetized monkeys. One-minute occlusion of the circumflex (CIRC) coronary artery resulted in marked negative chronotropic responses and consistent alterations in atrial electrograms. These responses were dependent on interruption of flow to a small proximal CIRC branch, and postmortem examin...

The nature and mechanisms of pulmonary vascular responses which follow miliary pulmonary embolism were examined in intact dogs in which the isolated left lower lobe was perfused at constant blood flow. Embolization of the lung with plastic microspheres increased total pulmonary vascular resistance, whereas, in contrast, vascular resistance of the isolated perfused left lower lobe which was prot...

Methods were devised for the selective alteration of parasympathetic control over the sinoatrial (SA) or the atrioventricular (AV) node in anesthetized, thoracotomized mongrel dogs. Two epicardial sites were located at which parasympathetic nerve fibers enroute to the SA or the AV node could be stimulated or blocked. Selective nerve stimulation was accomplished with brief pulses (0.05 msec), an...

Changes in left ventricular performance, stroke volume, and peripheral vascular resistance were studied in dogs after combined and separate stimulation of the aortic and carotid chemoreceptors. Selective stimulation of the aortic chemoreceptors produced an immediate increase in myocardial contractility as judged by the force developed by a strain gauge arch sewn into the left ventricular myocar...

Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in animals. We have examined whether baroreflex control of cardiac sympathetic nerve activity (CSNA) and/or cardiovagal baroreflex sensitivity are altered at the onset of spontaneously occurring motor behavior, which was monitored wi...

We determined the sympathetic and parasympathetic control of heart rate (HR) and the sensitivity of the cardiopulmonary receptors after selective carotid and aortic denervation. We also investigated the participation of the autonomic nervous system in the Bezold-Jarish reflex after selective removal of aortic and carotid baroreceptors. Male Wistar rats (220-270 g) were divided into three groups...

We investigated the effects of the sensory neuropeptide substance P (SP) on amylase and fluid secretion in the isolated vascularly perfused rat pancreas. SP inhibited CCK-induced amylase release and secretin-induced juice flow via the pancreatic duct in a dose-related fashion. Threshold inhibition occurred following addition of 10-10 M SP to the perfusate, and maximal inhibition was seen with 1...

This study was designed to test the hypothesis that hyperventilation-induced bronchoconstriction (HIB) results from the combined effects of prostanoid and leukotriene metabolism. A bronchoscope was used in anesthetized dogs to record peripheral airway resistance and HIB before and after combined treatment with inhibitors of cyclooxygenase (indomethacin) and 5-lipoxygenase (MK-0591). Bronchoalve...