OBJECTIVE To examine the relationship between baroreflex sensitivity and neurohormonal activation in patients with an acute myocardial infarction. METHODS Baroreflex sensitivity, plasma noradrenaline, atrial natriuretic factor, endothelin-1, and plasma renin activity were measured in 37 male patients about 10 days after their first myocardial infarction, and in 15 healthy controls. Baroreflex...

1. We have monitored intra-arterial pressure continuously throughout the day and analysed every beat by computer. 2. Baroreflex sensitivity (ms/mmHg) was measured four times a day (07.00, 12.00, 17.00 and 20.00 hours) in seven patients and three times a day (07.00, 12.00 and 17.00 hours) in 23 patients. The diurnal variation of baroreflex sensitivity in individual patients was 0--5.3 ms/mmHg an...

Arnold AC, Diz DI. Endogenous leptin contributes to baroreflex suppression within the solitary tract nucleus of aged rats. Am J Physiol Heart Circ Physiol 307: H1539–H1546, 2014. First published September 26, 2014; doi:10.1152/ajpheart.00282.2014.—The decline in cardiovagal baroreflex function that occurs with aging is accompanied by an increase in circulating leptin levels. Our previous studie...

BACKGROUND Abnormalities in baroreflex control of heart rate may be important in the pathogenesis of essential hypertension. METHODS AND RESULTS To investigate the influence of heredity on baroreflex function, we measured baroreflex sensitivity in 40 untreated patients with essential hypertension grouped by the presence (FH+) or absence (FH-) of a family history of hypertension and in 24 norm...

It is well established that GABAergic inputs to the paraventricular nucleus of the hypothalamus (PVN) tonically suppress heart rate and the activity of several sympathetic nerves. However, whether GABA similarly inhibits PVN control of baroreflex function has not been previously investigated. To test this hypothesis, it was determined whether microinjection of the GABA(A) antagonist, bicucullin...

We investigated the effects of chronic subcutaneous treatment with centrally-acting antihypertensive agents moxonidine, rilmenidine, and clonidine on the baroreflex control of heart rate (HR) in conscious normotensive rabbits over 3 weeks. Infusions of phenylephrine and nitroprusside were performed at week 0 and at weeks 1 and 3 of treatment to determine mean arterial pressure (MAP)-HR barorefl...

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...

Despite accumulated knowledge on human baroreflex control of muscle sympathetic nerve activity (SNA), whether baroreflex control of muscle SNA parallels that of other SNAs, in particular renal and cardiac SNAs, remains unclear. Using urethane and alpha-chloralose-anesthetized, vagotomized and aortic-denervated rabbits (n = 10), we recorded muscle SNA from tibial nerve by microneurography, simul...

In this study the baroreflex sensitivity of conscious, juvenile, spontaneously hypertensive rats (SHRs) was compared. The study population consisted of 19 eight-week-old male SHRs. The baroreflex sensitivity was quantified as the derivative of the variation in heart rate (HR) and the variation of mean arterial pressure (baroreflex sensitivity = ΔHR/ΔMAP). MAP was manipulated with sodium nitropr...

Baroreflex regulation appears in different species at different points in embryonic development. This study was designed to understand the development of the baroreflex in embryos of the American alligator at four different points of embryonic development (60%, 70%, 80% and 90% of a total incubation period of 72 days) and in 1-week-old hatchlings. Data from a separate study on 1-year-old alliga...