PURPOSE To compare baroreflex sensitivity among conscious rats of the same strain. METHODS Male WKY rats (eight weeks old) were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP) and heart rate (HR). Baroreflex gain was calculated as the ratio between variation of HR in function of the MAP variation (?HR/?M...

The purpose of this study was to examine the effects of skin cooling and heating on the heart rate (HR) control by the arterial baroreflex in humans. The subjects were 15 healthy men who underwent whole body thermal stress (esophageal temperatures, approximately 36.8 and approximately 37.0 degrees C; mean skin temperatures, approximately 26.4 and approximately 37.7 degrees C, in skin cooling an...

OBJECTIVE We evaluated heart rate variability biofeedback as a method for increasing vagal baroreflex gain and improving pulmonary function among 54 healthy adults. METHODS We compared 10 sessions of biofeedback training with an uninstructed control. Cognitive and physiological effects were measured in four of the sessions. RESULTS We found acute increases in low-frequency and total spectru...

AIM To study baroreflex maturation by measuring, longitudinally, baroreflex sensitivity in preterm (gestational age 24-37 weeks) and full term infants. METHODS Baroreflex sensitivity was quantified once a week, one to seven times, by a totally non-invasive method. RESULTS Baroreflex sensitivity at birth was lower in the preterm infant and increased with gestational age. It also increased wi...

Neurogenic pulmonary edema (NPE), which is induced by acute spinal cord compression (SCC) under the mild (1.5 %) isoflurane anesthesia, is highly dependent on baroreflex-mediated bradycardia because a deeper (3 %) isoflurane anesthesia or atropine pretreatment completely abolished bradycardia occurrence and NPE development in rats subjected to SCC. The aim of the present study was to evaluate w...

Previous human studies have shown that large-artery stiffness contributes to an age-related decrease in cardiovagal baroreflex sensitivity. Whether this is also true with sympathetic baroreflex sensitivity is unknown. We tested the hypothesis that sympathetic baroreflex sensitivity is associated with the stiffness of baroreceptor segments (the carotid artery and the aorta) in elderly individual...

The lateral septal area (LSA) is a limbic structure involved in autonomic, neuroendocrine and behavioural responses. An inhibitory influence of the LSA on baroreflex activity has been reported; however, the local neurotransmitter involved in this modulation is still unclear. In the present study, we verified the involvement of local LSA adrenoceptors in modulating cardiac baroreflex activity in...

BACKGROUND Continuous systolic blood pressure (SBP) and interbeat intervals (IBI) recordings reveal sequences of consecutive beats in which SBP and heart rate change in opposite direction, representing negative feedback baroreflex mechanisms, as well as sequences in which SBP and heart rate change in the same direction (non-baroreflex), believed to represent feedforward control mechanisms. The ...

BACKGROUND Isoflurane inhibits baroreflex control of heart rate (HR) by poorly understood mechanisms. The authors examined whether suprapontine central nervous system cardiovascular regulatory sites are required for anesthetic depression. METHODS The effects of isoflurane (1 and 2 rat minimum alveolar concentration [MAC]) on the baroreflex control of HR were determined in sham intact and midc...