Activation of the vestibular otolith organs with head-down rotation (HDR) increases muscle sympathetic nerve activity (MSNA) in humans. Previously, we demonstrated this vestibulosympathetic reflex (VSR) elicits increases in MSNA during baroreflex unloading (i.e., lower body negative pressure) in humans. Whether such an effect persists during baroreflex loading is unknown. We tested the hypothes...

Sleep syncope is a recently described form of vasovagal syncope that interrupts sleep. The pathophysiology of this condition is uncertain but a 'central' non-baroreflex-mediated trigger has been suggested. In the present study, we tested the hypothesis that patients with sleep syncope have abnormal sympatho-vagal responses to non-baroreflex, but normal responses to baroreflex stimuli. We collec...

ANG II alters the short-term blood pressure buffering capacity of the baroreflex in many adult animals. In embryonic chickens, high plasma ANG II levels contribute to baseline mean arterial pressure (MAP, kPa) without changing heart rate (ƒH, beats/min). We hypothesized, on the basis of these features, that an ANG II-induced reduction in baroreflex sensitivity is present in embryonic chickens a...

Mild lower-body negative pressure (LBNP) has been utilized to selectively unload cardiopulmonary baroreceptors, but there is evidence that arterial baroreceptors can be transiently unloaded after the onset of mild LBNP. In this paper, a black box mathematical model for the prediction of diastolic blood pressure (DBP) variability from multiple inputs (systolic blood pressure, R-R interval durati...

Bilateral carotid body tumor resection causes a permanent attenuation of vagal baroreflex sensitivity. We retrospectively examined the effects of bilateral carotid body tumor resection on the baroreflex control of sympathetic nerve traffic. Muscle sympathetic nerve activity was recorded in 5 patients after bilateral carotid body tumor resection (1 man and 4 women, 51+/-11 years) and 6 healthy c...

INTRODUCTION We hypothesized that repeated respiratory straining maneuvers (repeated SM) designed to elevate arterial BPs (arterial baroreceptor loading) would acutely increase baroreflex responses. METHODS We tested this hypothesis by measuring cardiac baroreflex responses to carotid baroreceptor stimulation (neck pressures), and changes in heart rate and diastolic BP after reductions in BP ...

Adriamycin cardiotoxicity is associated with oxidative stress in the presence of globally depressed cardiac function. It is unknown if there is a similar profile with early diastolic changes and how it relates to baroreflex control of circulation. In this study, we evaluated baroreflex control of circulation in adriamycin-treated Wistar rats compared with controls, using invasive blood pressure...

In animals, electric field stimulation of carotid baroreceptors elicits a depressor response through sympathetic inhibition. We tested the hypothesis that the stimulation acutely reduces sympathetic vasomotor tone and blood pressure in patients with drug treatment-resistant arterial hypertension. Furthermore, we tested whether the stimulation impairs the physiological baroreflex regulation. We ...

Arterial baroreflex sensitivity, plasma norepinephrine (NE) and epinephrine (E), and pressor and depressor responses were assessed in 25 patients with essential hypertension and 29 normotensive control subjects. Sensitivity of the cardiac limb of the baroreflex was determined by blood pressure and interbeat interval responses associated with the Valsalva maneuver, externally applied neck suctio...

Maliszewska-Scislo M, Chen H, Augustyniak RA, Seth D, Rossi NF. Subfornical organ differentially modulates baroreflex function in normotensive and two-kidney, one-clip hypertensive rats. Am J Physiol Regul Integr Comp Physiol 295: R741–R750, 2008. First published July 2, 2008; doi:10.1152/ajpregu.00157.2008.—During activation of the renin-angiotensin system, hindbrain circumventricular organs s...