Baroreflex activation therapy through electrical carotid sinus stimulation.

An imbalance between cardiovascular parasympathetic and sympathetic activity towards sympathetic predominance has been implicated in the pathogenesis of treatment-resistant arterial hypertension and heart failure. Arterial baroreceptors control efferent cardiovascular autonomic activity and have, therefore, been recognized as potential treatment targets. Baroreflex activation therapy through electrical carotid sinus stimulation is a device-based approach to modulate cardiovascular autonomic activity.

Impact of Daily Lower-Body Negative Pressure or Cycling Followed by Venous Constrictive Thigh Cuffs on Bedrest-Induced Orthostatic Intolerance.

Background: Orthostatic intolerance occurs following immobilization in patients on Earth and in astronauts after spaceflight. Head-down tilt bedrest is a terrestrial model for weightlessness and induces orthostatic intolerance. We hypothesized that lower-body negative pressure (LBNP) or cycling followed by wearing venous constrictive thigh cuffs mitigates orthostatic intolerance after head-down tilt bedrest.

Cardiopulmonary deconditioning and plasma volume loss are not sufficient to provoke orthostatic hypertension.

Orthostatic hypertension, defined by an increase of systolic blood pressure (SBP) of ≥20 mmHg upon standing, harbors an increased cardiovascular risk. We pooled data from two rigorously conducted head-down tilt bedrest studies to test the hypothesis that cardiopulmonary deconditioning and hypovolemia predispose to orthostatic hypertension. With bedrest, peak VO decreased by 6 ± 4 mlO/min/kg (p < 0.

Effects of 30 days bed rest and exercise countermeasures on PBMC bioenergetics.

Aim: Altered mitochondrial function across various tissues is a key determinant of spaceflight-induced physical deconditioning. In comparison to tissue biopsies, blood cell bioenergetics holds promise as a systemic and more readily accessible biomarker, which was evaluated during head-down tilt bed rest (HDTBR), an established ground-based analog for spaceflight-induced physiological changes in humans. More specifically, this study explored the effects of HDTBR and an exercise countermeasure on mitochondrial respiration in peripheral blood mononuclear cells (PBMCs).

Glucose-sensitive hypothalamic nuclei traced through functional magnetic resonance imaging.

Introduction: Hypothalamic glucose-sensitive neural circuits, which regulate energy metabolism and can contribute to diseases such as obesity and type 2 diabetes, have been difficult to study in humans. We developed an approach to assess hypothalamic functional connectivity changes during glucose loading using functional magnetic resonance imaging (fMRI).

Methods: To do so, we conducted oral glucose tolerance tests while acquiring functional images before, and 10 and 45 min after glucose ingestion in a healthy male and cross-sectionally in 20 healthy participants on two different diets.